Most workplace investigations fail for predictable reasons: unclear scope, vague allegations, weak evidence handling, poor procedural fairness, and reports that don’t show reasoning. Fixing these isn’t about being ‘more formal’ – it’s about being more disciplined at the start and clearer throughout.
Mistake 1: starting with a conclusion (or a preferred outcome)
When leaders say ‘we just need this wrapped up’, investigations become outcome-driven. That’s how
credibility collapses. If the process looks like a rubber stamp, expect escalation.
A defensible process starts with an open question: what happened, on the evidence?
Mistake 2: allegations that can’t be tested
Allegations like ‘bullying’ or ‘toxic behaviour’ are labels, not facts. If allegations aren’t framed as behaviour,
timeframe and context, you cannot test evidence and you cannot give the respondent a fair opportunity to respond.
This is where many internal investigations fall over: they investigate a feeling rather than an allegation.
Mistake 3: scope creep disguised as ‘thoroughness’
Scope creep often comes from good intentions. Someone raises ‘one more thing’, and suddenly you’re
looking at a year of history. The longer it goes, the less safe it feels and the harder it is to communicate.
Thoroughness is not the same as breadth. Scope should widen only when it is necessary and documented.
Mistake 4: evidence contamination
Early ‘informal chats’, managers ‘getting their side’, or witnesses comparing notes can contaminate
accounts. Once evidence is contaminated, integrity is hard to restore.
Contain early. Preserve evidence. Plan interviews. Then move.
Mistake 5: reports that don’t show reasoning
A report that repeats statements and then concludes ‘substantiated’ is not defensible. Where evidence
conflicts, the report must explain why one account was preferred and how evidence was weighed.
Decision-makers need more than conclusions. They need the working.
FAQs
What is the biggest investigation mistake?
Unclear allegations and scope. Everything else flows from that.
Can informal resolution happen during an investigation?
Sometimes, but be careful. Resolution should not undermine fact-finding or fairness, and should never
pressure a complainant or respondent.
What happens if an investigation is challenged later?
Your process and report become the evidence. If they are weak, organisations often re-run investigations or settle disputes they could have managed.