Oh that sounds like a great scene in the sense that she was in tune with how you were feeling.

Of course many domme use a safeword, and it never even comes up. It is a good idea if the domme ever gets distracted. A major part of it for me is to focus on the reactions of my submissive.

I do love bondage, but have occasionally had someone have a freak out from claustrophobia, but instead of stopping completely, I de-escalate the situation and transition to something else.