Check in online, and get to LAX by about 6:15, and he should be OK. If he's only got carry-on bags, he should get dropped off at the UA international terminal at T6. There are still 3 Mr. Chickens there. Of course, if he has a problem he's got to walk down to T7.

So, check in online, go to T6. If the line at the security entrance between T6 and T7 is too long, turn around and go to the T6 line back towards the Contintenal counters. That line should be totally empty at that time.

If he's going to check bags, he's going to have to go to T7, and I'd guess he'd best be there by 6AM. At the latest.