This is why I make sure I talk in a calm voice about the destruction some techniques can cause. I just comment on it: "And if I can't control him here, I'll take the shoulder out." I talk at other times (not during technique) about the repercussions of self-defense decisions, but in that moment, I want it to be clear to them that if I've been put in a position of having to defend, I can't really afford to be nice unless it is clear I absolutely outclass the guy (and even then, I'm taking a risk to do so). I need to end this as quickly as possible. If that means he has a concussion, broken wrist, or whatnot, that's what I'll do.
"I'm a really nice guy, until I'm not."