Section 02
What a defensible workplace investigation involves in Ontario — the duties, the process, and the questions employers ask before they start.
A workplace investigation is a structured, impartial fact-finding process: when there’s a contested allegation — harassment, violence, discrimination, theft, serious misconduct — it’s how an employer works out what actually happened before deciding what to do about it.
In Ontario you often don’t get to choose whether to investigate. The trigger threshold is low: a formal complaint, an offhand verbal report, or a manager simply noticing something can all engage your duty. You don’t need a signed form, and you can’t wait to be asked — once you’re aware of a possible incident, you’re expected to act.
Get the process right and a hard decision becomes defensible. Get it wrong and the investigation itself becomes the liability — whatever the original complaint was worth. This page frames what’s involved and points you down to the sourced notes that back each part.
Ontario law
Primary legislation and binding precedent — the fixed points. Everything after this is judgment.
Verified
The duty
If you become aware of possible workplace harassment, you must ensure an investigation is conducted that is appropriate in the circumstances — and inform both the worker and the alleged harasser, in writing, of the results and any corrective action.
OHSA, s. 32.0.7 Occupational Health and Safety Act (Ontario)
OHSA harassment program ›Verified
What counts as harassment
Harassment is a course of vexatious comment or conduct against a worker that is known — or ought reasonably to be known — to be unwelcome. The definition expressly reaches conduct online — “virtually through the use of information and communications technology” — and includes workplace sexual harassment.
OHSA, s. 1(1) Occupational Health and Safety Act (Ontario)
The definition in the Act ›Verified
The standard of proof
You decide on the balance of probabilities — whether it’s more likely than not the conduct happened. There is no higher bar for serious allegations, and the criminal “beyond a reasonable doubt” standard has no place in a workplace investigation.
F.H. v. McDougall, 2008 SCC 53 Supreme Court of Canada
Findings & report ›General information about Ontario law, not legal advice.
Practice — not law
The law sets the standard — “appropriate in the circumstances.” It doesn’t tell you how. This is the method: six stages, and the place each one tends to fail. None of it is a legal citation — it’s what the work involves when it’s done well, and where most investigations come apart.
Define the specific allegations, the mandate, and any interim measures — then choose who investigates. The investigator has to be genuinely neutral: not the respondent’s manager, not anyone with a stake in the outcome.
What makes an investigation defensible ›Where it goes wrong Bias — real or just perceived — is the most common and most expensive failure. In a small company the obvious internal candidate often reports to one of the parties, which is what pushes serious files to an outside investigator.
Give the respondent the specific allegations — conduct, dates, context — in enough detail to actually answer, ideally in writing. Interview the complainant, then the respondent, then witnesses, with open, non-leading questions and a support person where appropriate.
Conducting the interviews ›Where it goes wrong Vague allegations — “bullying,” “a toxic attitude” — can’t be answered or tested. Leading questions taint the evidence, and so does never giving the respondent the case to answer.
Collect documents and testimony, look for corroboration, and check context — a damning-looking message can read differently in the full thread. Investigations aren’t courts; hearsay isn’t banned, but a finding shouldn’t rest on it alone.
Evidence & credibility ›Where it goes wrong Scope creep. Letting “one more thing” turn a focused complaint into an open-ended inquiry exceeds the mandate — itself a fairness error.
Where accounts conflict, test each against the probabilities a practical person would accept — internal consistency, corroboration, plausibility, motive — and write down why you preferred one account over the other.
Where it goes wrong Deciding who’s lying from body language or nerves. Demeanour is not a lie detector — courts have said so repeatedly — and a credibility finding with no reasons is indefensible.
On each allegation, reach a finding: substantiated, partly, or not. Decide; don’t default to “inconclusive.” The investigator finds facts and, where the mandate asks, whether a policy was breached. The discipline decision belongs to the employer.
Findings & report ›Where it goes wrong Conflating fact-finding with punishment — the investigator setting the penalty, or the employer disciplining before the facts are in.
Tell each party the result and any corrective action — in Ontario, in writing, within ten days. Keep a secure file, hold confidentiality, and actually act on substantiated findings.
After the investigation ›Where it goes wrong Reprisal is the most dangerous post-investigation trap. A schedule change or a quiet “restructuring” can sink you — even where the original complaint was never substantiated.
The full catalogue of failure modes — how investigations go wrong ›
Verified
The duty
Once you’re aware of possible workplace harassment, you must ensure an investigation appropriate in the circumstances — and tell both parties, in writing, the outcome.
OHSA, s. 32.0.7 Occupational Health and Safety Act (Ontario)
OHSA harassment program ›
Article Three Courages Every Leader Should Know Talk to an investigator Book a consultation A real decision
A trained, neutral insider can handle a lot. Some files need a genuinely independent outsider — and choosing wrong is itself a fairness risk. Here’s when each fits.
When it fits
When it fits
Two things to know either way: an external investigator’s findings aren’t legally binding on a court or tribunal, and a lawyer acting as investigator should be retained as an independent investigator, not as your counsel. What makes an investigation defensible ›
Before you start
More often than employers expect — yes. In Ontario the trigger threshold is low: a formal complaint, an offhand verbal report, or a manager simply noticing something can all engage your duty. You don’t need a signed form, and once you’re aware of a possible incident, you’re expected to act rather than wait to be asked.
What an investigation is, and when one’s needed ›Usually not the right call. The investigator has to be impartial and free of any reporting relationship to the people involved — a manager investigating their own team rarely clears that bar, however fair they’d try to be. When the respondent is senior, the matter is complex, or litigation is likely, that’s when a neutral outside investigator earns its cost.
Impartiality and the internal-vs-external decision ›Two, in Ontario. The investigation itself should be done promptly — Ontario’s guidance points to 90 days or less unless there’s a real reason it takes longer. And once it’s concluded, you must inform the parties of the results and any corrective action in writing, within ten days.
Delay, and the 90-day guideline ›Not always. A trained, genuinely neutral internal person can handle lower-complexity matters faster and cheaper. Go external when impartiality is in doubt, the respondent is senior, the matter is complex or high-profile, litigation is likely, or there’s simply no conflict-free internal investigator — which, in a small company, is often the case.
What makes an investigation defensible ›Often, yes — and this one catches employers out. Common-law “just cause” and the Employment Standards Act’s “wilful misconduct” are two different tests, and the ESA bar is higher. You can have cause to dismiss without notice at common law and still owe statutory termination and severance pay.
Just cause vs. ESA wilful misconduct ›No. There’s no legal requirement in Ontario to use progressive discipline, and no “three warnings” rule. It’s a management best practice and an evidence-building strategy, not a statute. What it does do is build a documented, defensible record — which is what matters if a dismissal is ever challenged.
Progressive discipline in Ontario ›The pyramid
Talk it through
That’s usually the first thing worth figuring out — before anyone’s interviewed and before a misstep is baked in. If a complaint has landed, or you just want a neutral read on whether to handle it inside or bring someone in, let’s talk it through.