Another out of the loop expert, imo.
His story was confirmed by people on the ground there, according to him. Either way, you're choosing to believe one second-hand version of events over another second-hand version of events.
I wouldn't immediately trust a government "investigation" considering these investigations always seem to find no wrongdoing on the military's part.
Paid with 'rat dollars, more likely. he was "at the base" not at the ambush. He doesn't know what happened except what he was told--or made up. The longstanding Army doctrine is, when encountering an ambush, always always attack into it, both to engage the enemy and to exit the kill zone. The reason is that if you linger in the kill zone, you will be--killed. Duh. But one wouldn't expect a civilian truckdriver to figure that out.