@cepha She's awful. I hated the show because they felt they needed to heap abuse on the participants to make for good TV and to push them beyond healthy limits.
But, again, there are people that like that sort of thing, so she's the trainer they like. It's their flavor so I don't knock it. They are 100% focused on performance and anything to eke it out is good to them.
(I have a different method for maximum performance and there are a lot of people that would prefer Julian over what I'm doing.)
In any case, I walk out of classes if they're too slow, I don't like the music, it's too crowded, I need to use the bathroom, I want to talk to a friend, I want a drink of water, I need to take a phone call...and on and on. I'm a grown woman. I don't need permission from the teacher to go to the bathroom. And if you stop to explain - well now you are being disruptive to the rest of the class.
If she said something, laugh and keep walking. You can't allow people to be so disruptive to your inner peace.
And don't regret. You learned something valuable today, that you have more power over how you experience other people than you think. I hope you feel much better about it now.