I agree. But the only thing i can think of where this could not be the case is if when SIL left to drop NG off, AG got ready for bed and fell asleep. If for some chance they didn’t share a bedroom, as even some healthy couples don’t, i could see how that could leave some room for him to sneak in and out and be back by sunrise after whatever could have happened after the 1-2 am timeframe.If T is involved, I think it is highly likely that A is involved too. She would have said something if he had taken hours to come home after dropping her off, or probably noticed if he left again late at night.
just thinking out loud don’t take me too seriously