Source on Occam's razor being anything more than a philosophical framework? Kind of silly to even bring that up in this scenario without looking at the possible motivations or lack thereof.
I would agree, except it is not some random average guy in a vehicle.
This was a concern citizen, who was a whistleblower against his employer, who had just begun a legal deposition, and there are billions of dollars at stake.
So - the scenario possibly just isn't that simple.
Our scenario is this: There's a guy in a vehicle. He is holding a gun. He has a gunshot wound. He has been under a lot of stress.
Explanation 1: The guy shot himself. Number of entities (people) required: 1
Explanation 2: Someone else shot the guy and staged the scene to look like a suicide. Number of entities (people) required: 2
Occam's razor says suicide is the most likely explanation