On the pictures you posted, it looked as if he didn't have any teeth left at all. It's great you can let him stay in the bathroom to recover. He may be angry with you for the first few days, but he will soon relax and mingle with the others.

When Fister was fixed, vaccinated and ear marked, they kept him for 4-5 days, then released him in the yard with his mother. They were both doing fine - and started coming closer to us.

Give him some kisses from me when you get home!