Not necessarily, it’s possible he could have renewed his visitor visa repeatedly, Canada can be quite generous in that request.
He’s still working illegally though which won’t end well when caught. It’ll happen at some point, particularly if he’s crossing in to the US regularly which makes it almost guaranteed that at some point he’ll be stopped and questioned, his phone searched etc.
I agree with @mam521, he needs to go home asap, Canada’s not an option for his visa application anyway as he’s not resident there.