I would be curious about why that was wrong (rather than feeling bad about myself), I would be surprised and ask, "It's not what you have been teaching me? Then what?" It seems an odd question for a T to ask though, to me; I'm not sure I am understanding the context, what response she was trying to get and/or what she meant by "hurt". An older man and a young girl as combatants are very unmatched; it seems unlikely to me that the young girl could get in a position to hurt the man. I'd recommend she tell a trusted adult so he could be caught and make sure I did not get to thinking it was my fault in any way. I would not listen to the man hurting/trying to hurt me, would not believe anything he said to me. I'd find bigger, badder adults to sic on him :-)

But I do not think T's expressing how they feel, whether anger, disappointment, pride, boredom, etc. is about boundaries at all. A boundary is a stated principle that can only be crossed, on purpose. It usually is an unequivocal statement which has a consequence for crossing it attached. "If you tell me you are suicidal, I will have you hospitalized" is not a "threat", it is a boundary of how a T operates their business. "If you email me more than once a week, I will revoke your email privileges" is just their personal rule for doing therapy. It's not about fair/not fair, nice/not nice, it is just the way they do business.

But you cannot cross a person's boundaries before they are stated! If a person does not like something, they cannot know until it "happens" for them not to like! Just because a T has a boundary with you does not mean they have that boundary with all clients and vice versa. Emailing may not be a good idea for your therapy but someone else might do better with it or, at certain stages in therapy this or that boundary may have to be imposed, as issues come up. It's not meant to be a maze or obstacle course, boundaries are used to clear paths and widened/clear roads to make it easier for us.

But that is what makes interaction with T's so interesting/challenging. Boundaries are rules but anger is not about "rules" but about interaction between individuals. Being disrespectful is not so much about crossing boundaries as about being. . .disrespectful!

The way you tell the difference is if it applies to everyone; versus if it is just in this case, with this person, in this situation. If it applies to everyone, it is an interaction/social rule; kind of like having to learn how close to physically stand near people or how long to keep hold of a person's hand when you are shaking it, etc. That takes practice and eventually you learn little cues for the people in your life versus strangers (who get the "average" :-) etc. But a boundary is like a "contract" between two individuals only. "Do/Do not do X or Y will happen" tells another where a boundary is. But it may not exist or be in that location, have that consequence, etc. with someone else.

True, one person might get angry about something and say/imply, "Don't do that" and you may feel it is a boundary but boundary setting usually happens in a calmer, more straightforward way. You probably do not want to step on someone's toes again, if you do once but, there is no reason to feel bad about accidentally stepping on someone's toes! It's not like you meant to or were necessarily careless. If you mean to, if someone draws a line and you then cross it anyway, for whatever reason (testing them, in anger, to hurt them, etc.) that's boundary crossing.

If someone says "Ouch!" when you step on their toes, that does not mean you aren't going to accidentally step on their toes again and they are probably not going to make a "rule" that says, "Don't step on my toes or I will terminate therapy with you" Toe stepping on will come up all the time (and the person will say "Ouch" each time :-) while you learn to dance but boundary crossing should not come up at all. "If you want to learn to dance, you must stay in this room or I cannot teach you anymore" means you can't wander around during lessons, do your own thing while the teacher is trying to teach. If you do, the teacher will not teach you anymore, will ask you to leave the room for good until you are able to abide by that rule.