The string of curses that filtered through Gabriel's brain were quite a bit more than he would have ever deemed appropriate to say out loud. He was torn between trying go after himself (the other man?) and try and explain what was going on and staying with the hopes of cooling the worst of Peter's temper. He highly doubted that Claire would be able to at the moment... Or he could just leave the task to Nathan? Peter's brother was likely to have more success than he could ever hope to manage.
There were a dozen things he should have done differently. He shouldn't have waited. He should have been more overtly sympathetic rather than trying to play it off to try and keep from making Peter angrier. He shouldn't be frozen to the goddamn spot staring with his jaw unhinged at the front door when he could just as easily followed him and attempted to explain.
Why wasn't he moving?!
"I..." It was a stammer and quite a bit too late as he stared at the closed door. "I didn't... I wasn't... I only wanted to help," His voice dropped, head hanging as he tightened in on himself. "I should have stayed on the stairs."