>the burden of proof in my mind is on the company
Because that is not how the courts operate. It is up to the person making the accusation (which in this case is the employee accusing Amazon of an unjust firing) to provide proof.
If you want to start dismissing all "he said/she said" arguments, then we might as well shut down this entire thread. We are never going to get any further than "he said/she said" unless someone in this thread has insider knowledge of this situation and is willing to break privacy agreements.