My family are all window cleaners, and employed a fair amount of lads over the years, nearly all commercial, well apart from me, I am mostly domestic, well maybe 60/40 domestic/commercial
my dad never gave a hoot if employees did house's on their own time, neither does my brother, but it was explained from the start it was their own kit and they were not insured.
When I did employ I couldn't care if my lad did houses on his estate in his own time, but again I explained he wasn't insured and the first time I got a call asking when I was coming to clean the windows he would be sacked, and made it clear he would need his own kit and ladder if he did do it, and I would not be responsible for anything he did in his own time
however in this case the guy took a van and couldn't drive legally, a big no in my books. he was using your van and equipment and probably your company name, so he was totally wrong, but you need to make clear from the start what is expected. I probably would have sacked him there and then, although I wouldn't have taken any money from him.
but to guy david who threatened violence and wrecked vans, you are a bampot, what did you expect after the guy took a van fraudulently, do you employ? you might feel differently if you did.