Triggered (I hate that word)

So I've been out for over 2 years and for part of that I've been with my new partner. The other day We were a Taco Bell and he was a little annoyed as they'd missed something, and as he was talking to the worker I moved a chair and he said "iI I wasn't interrupted!" then he froze, it's was a split second but he saw fear in my eyes. He collected himself and apologised and sorted what he needed to. It was that brief I didn't register fear but he saw it. With my ex that annoyance would turn into hours of verbal and psychological abuse. He didn't. I also know he would of collected himself regardless of if I showed fear. We knew it would happen. He's aware enough that he can collect himself and not sink into that anger or annoyance.

I am with someone who has a good level of emotional maturity that he can register and correct course. I knew he would trigger me at some point but I feel bad. For me this isn't a red flag as he corrected course and knows how to stop.

I know I am safe with him. I just wish there was a delete button for the damage caused by others.