It's understandable to have a lot of over-time as a new-comer. After the ramp-up period of time, there should not be much outrageous overtime.
Excessive over-time will not bring him any benefit but damamge --- the boss would tend to view he as too slow.
Can he dial-in through internet to work from home outside regular business hours? Then, you will know more of what exactly is going on.
Good luck.