It's horrible initially. The damage does fade with each month. After two years, it's neglible for scoring, and most banks don't worry about it.
What else is going on with his reports? If this is the absolutely only baddie showing, he can just grovel and beg and hope that it's not held against him. If he has other lates, it's going to look like the continuation of a pattern of irresponsible handling of credit. (I'm projecting the creditor's thoughts here --please don't tear me up!)
I don't suppose there's any way he can delay the loans until at least 6 months after whatever month the late posted? That would help some. The longer a stretch of clean credit both before and after the late, the more likely it is that a lender will acknowledge it as a one-time mistake, and not a sign of future problems.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007