Brian's DV on Gabby and speeding/traffic stop occurred on the 12th? And the flight on the 17th? (correct me if I'm wrong). In any case those 4 days, 13th thru 16th must have been terrible, really horrible. Real doozies. He probably inflicted more physical and mental pain on her. There's a reason the trip occurred so quickly after his hitting/slapping her, grabbing her face, attempting carjack of her vehicle, speeding, reckless driving, embarrassing her in public, lying, and, IMO not allowing her to complete her work to upload.
Charitably (see I'm trying) he may have realized he was spiraling out of control, and may have nearly murdered her in those 4 days, or fantasized about it, and realized he needed help. Maybe once he got home and was coddled, it kind of subsided and he returned, having stole her keys in the meantime to maintain control.
Or, maybe he saw her vacillating and thinking of ending the trip, ending THEIR relationship. If only.
When he got back, all the problems were still there in his mind, ready for his own self-ignited explosion towards her.
IMO