Employee fired for reporting a serious injury, but in a roundabout way - How difficult is it to prove the employer's motive?

Question

As per my previous question How do Florida's labor laws protect employees injured when asked to do something unreasonable?

A girl working in Florida insisted on filing an injury report after being asked not to. She was then, after working there 6+ months with zero write-ups, given three write ups within a span of hours for frivolous violations, including her shirt coming un-tucked while reaching upward for something, and mentioning the incident to a co-worker (who then went tell management she needs a doctor), which the management labeled as talking about non-work-related topics, and the third was so frivolous she's not even clear what it was for. She's on track to be fired on her next shift.

What would it take to prove motive in such a case in order to make a case that the company is breaking Florida Statute 440.205?

Coercion of employees.—No employer shall discharge, threaten to discharge, intimidate, or coerce any employee by reason of such employee’s valid claim for compensation or attempt to claim compensation under the Workers’ Compensation Law.

More specifically (for the scope of this site), what are the primary fundamental questions that would have to be answered "yes" to make such a case?

Answer 1

A plaintiff wins a civil claim by proving their case on the balance of probabilities - that is, is their case more likely than the defence case.

The court will decide if it is more likely that the employee was terminated for attempting to make a workers compensation claim or if it is more likely they were fired for the reason the company gives.

When I’m called upon to make such decisions I apply the duck test:

If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.

... even if someone is trying to tell me it’s a chicken.