AITAH for telling my girlfriend she was the perpetrator, not the victim, in her "trauma"?

My [25m] girlfriend [24f] and I have been dating for about a year. I'll call her Casey here. We have lived together for two months.

A few hours ago, Casey approached me saying that she wanted to talk about something "serious." At first, I didn't know what to expect, but she wanted to share something traumatic that had happened to her before we met, and she asked if I would be willing to listen. I of course said yes, I would, if she'd be willing to share.

Casey hesitated for a second, like she wasn't sure about telling me, but then gave me the full story. What happened was when she was a university student, she had a crush on a pizza guy. He worked at a small shop near her apartment, and he would often deliver to her. She wanted to ask him out, but she wasn't sure how, so she consulted her friends.

Her friend group talked over it, and then one brought up the suggestion of answering the door in lingerie. The others jumped onto the idea quickly, and while Casey had doubts, they quickly convinced her to try it. They apparently even went shopping for the lingerie together.

Casey put on makeup, did her hair, and ordered a pizza. When the guy came, she did exactly as her friends suggested: she opened the door in skimpy lingerie. The pizza guy initially didn't address it, but Casey, "desperate," pushed the topic. She asked him, "What do you think about my outfit?"

He responded, "Dude, please don't do that," and then left. At this point in the story, Casey was near tears, and she told me how embarrassed and sick she felt.

I almost expected more from the story, but she was finished. I then said, "Uh … you do realize that you weren't the victim, but the perpetrator, right?" She literally recoiled at this comment. She elaborated by blaming everybody else: her friends for "tricking" her, society in general, and even the pizza guy that she sexually harassed.

To this I responded that she's like those guys who touch themselves in hotels, intentionally getting the maids to walk in on them. She insisted it was completely different, and a full-blown argument ensued. She finished the argument with "I came to you to feel better and now I feel WORSE!" and stormed away.

I don't even know. I feel so disgusted with her right now. Was I the butthole for my comments when she felt vulnerable?