Post Incident Testing: To Test or Not To Test!

Workplace Training

By Logan Tannahill on October 2, 2025

By Logan Tannahill CEO, Shift OHS

Short version: In a serious or potentially serious event, don’t guess. Use the Matrix. It gives supervisors an “if-this-then-that” path so your response is consistent, legal, and fast and it keeps you out of the grey zone where hindsight and lawyers live.

Why a Matrix beats gut feel

Consistency over emotion. We remove bias and protect workers by following one playbook every time. Systems build great companies.
Clarity under stress. Make the right action the easy action. A simple decision tree turns chaos into checkmarks.
Extreme ownership. Your job is to act, not hope. The Matrix tells you exactly what to do next.

The 7 triggers that mean: “Use the Matrix now”

Use the Post-Incident Decision Matrix immediately when any of these are true:

A fatality occurred.
A worker was admitted to hospital.
There was an injury requiring immediate medical treatment off-site.
There’s disabling damage to a vehicle or equipment.
A member of the public was involved.
Performance cannot be fully discounted as a contributing factor.
The event is serious or potentially serious, even if facts are still developing.
These cues come straight from our training resources and the sample Matrix/decision tree your supervisors use on site.

What the Matrix decides (in plain language)

Who gets tested. Only those directly in the chain of acts/omissions leading up to the event. (No fishing expeditions.)
What gets tested. Both alcohol and drugs, that dual step matters and is supported by case law and policy best-practice.
How fast to move. Aim for ASAP, with clear time windows commonly used in protocols (e.g., alcohol within 8 hours; drugs within 32 hours) so evidence is meaningful and defensible.

The first 10 minutes

Secure the scene & people. Safety first.
Open your Matrix. Don’t rely on memory; follow the boxes.
Document facts, not feelings. Names, times, location, what happened, no diagnosis or speculation.
Decide with a second trained leader. Ask “What’s the question that leads us forward?” → Do Matrix criteria say test?
Act fast, transport safely. If testing is required, escort the worker; do not let them self-drive.

Legal & human lens (so you don’t trip over it later)

Duty to Inquire comes first. If behavior suggests a possible medical/mental-health or substance-dependence ground, you must inquire and investigate before adverse action. Reassign to non-safety-sensitive work or paid leave while you do.
Privacy & confidentiality are non-negotiable. Treat all fitness-for-duty info like health records “need-to-know” only and stored separately from personnel files.

What not to do

Don’t test “everyone who was nearby.” The Matrix limits scope to those in the causal chain.
Don’t delay until the next day. Windows matter for evidentiary value.
Don’t skip the alcohol test. Post-incident protocols call for both drugs and alcohol.

The mindset that wins

When an incident happens, speed and certainty create value. Your brand is built in these moments. Have the Matrix. Use the Matrix. That’s how we protect lives, reduce downtime, and keep regulators (and insurers) confident.

Final Thought: Culture Is Built in the Pause

The next time this happens, your supervisor won’t get a rehearsal. No pause button. No time to guess.

You’ll either have a system or a story you can’t take back. Let’s build the system now.

Ready to Shift?

Want a Quick Win - Download our free Post Incident Decision Matrix here, Or

Book your spot for The Reasonable Cause Supervisor Training today - Reasonable Cause Training. If this hit a little too close to home, that’s okay. We’re here to help you fix it, before it hits the fan.