How do I deal with doubts about my girlfriend’s experience?

TL;DR – My girlfriend got blackout drunk and something happened between her and another guy. I’m just not sure what.

\—–

My girlfriend (32F) and I (34M) have been together for about 7 years. She struggles with communicating about difficult or painful things, but she’s working on it with the help of a therapist. She has often hinted that “something happened” with a guy at work a couple years back, but would never reveal any details – not even if it was good or bad. She seems almost secretive about it, even though she is the one who randomly brings it up.

Today it finally came out that she thinks he sexually assaulted her, although she can’t say for sure. The story she told me is that they were at a work party and one of their co-workers “tricked them into getting really drunk.” She says she doesn’t really know what happened, but next thing she remembers is being half naked in bed as the guy is leaving her apartment.

Obviously this is a traumatic experience, and I know the worst thing I could do in this situation is blame the victim. And of course I know I should believe her. I really want to believe her. But…I can’t shake the feeling that something is a little suspicious.

Here’s why:

My girlfriend is no stranger to alcohol. We partied pretty hard in the past, and she has never blacked out drinking before or since. And she doesn’t think she was roofied – she says she woke up feeling more or less ok, not even too hungover.

However, I have seen my girlfriend when she’s drunk. She gets really friendly and does a lot of really dumb things. She often aggressively flirts with people, and she makes fast friends with total strangers. Just last week I overheard her giving her address to a group of randoms outside a bar and inviting everyone to her house after last call.

And here’s the thing – I know she thought this guy was attractive (it came up in conversation a long time ago; looking back I’m not sure if it was before or after the incident). She’s always been faithful as far as I know, but it would not be out of character for her to get physical and flirty while drinking with a co-worker she was into. In fact, that is exactly how she and I first hooked up.

How should I handle this? Statistics say that most sexual assault victims know their attacker. And this has all the signs – it seems like she was taken advantage of by someone she should have been able to trust. So I want to believe her and support her and make her feel safe. But it also seems within the realm of possibility that she drunkenly hooked up with this guy and is…trying to forget it? Pretend it didn’t happen?

Am I a piece of shit for even thinking this? Or am I right to be skeptical? I don’t know, but I’m driving myself crazy with these thoughts. I would love an outside perspective, if possible from a woman who might have had a similar experience. Any insight you could offer would be much appreciated.