I think this is the same guy who had to go home after getting the COVID alert to self isolate, after coming into work whilst waiting on test result to come through, and because he wasnt allowed to take the van home with him had no way of getting home, so ended up jumping in van with a colleague.
The story is too similar to not be
If thats the case, then the real reason for being dismissed is not just van sharing but van sharing whilst being alerted to self isolate which really you can have no excuses or justification for
Added to the fact of coming into work whilst waiting on test result in first place