I think I might've handled it about the same way you did. I probably would've called the brother, too, because I would've felt 'unsafe', unsteady, or unsure of reality for a moment. Be easy on yourself. You did your best, and that's all a person could ever do!!
I don't know for sure if I would do the same or not... Putting to real life practice the whole, "not everything needs a reaction" that I'm doing is helpful, and the situation you posted, were it me, would put that to the test.