I don't understand the language, but even if he claims that it doesn't make it true. Bones are pretty resilient and if there actually was a whole human in the cabin there should be a bit more of bones left among with helmet, metal bits and bobs from the gear and things like that.

However, it doesn't really matter if that's a ham bone or human remains. To me this doesn't seem like the driver was in the cabin when it caught fire (why would he, they're parked in a neat line) and whatever the trught might be war is nasty business for everyone involved and even if that's remains of the driver in the big picture that doesn't mean much.

At the end the destroyed cargo and equipment is far more valuable for the Ukraine than some Joe Nobody driving a truck. For us watching from a safe and warm place it doesn't make a huge difference either but personally I'd rather stick to verified facts than a rumour based on a short video from somewhere.