Actually, what are the legalities of Ad taking 3 weeks leave, and putting in his notice to leave on the first day of his holidays????
Happens all the time. Legal, well unless there is something in his agreement about it, just not really moral. Considering his situation though it might be a good idea. Just see if he can get all his leave paid in advance, I know when I did payroll I would sometimes be requested to pay leave money as someone was going overseas , rather then just pay the leave the normal pays.