I don't think it is so silly, really. If Christina was led to believe it was a girl's night out, but other people invited some guys she wasn't expecting, then that may have been significant. If she was fighting with HF and the girls called her up and said let's have a GNO, she may not have agreed to go if certain other people (guys) were going to be there. Maybe she was misled about the evening. We talked at length about the possibility of her being "set up" somehow. Her mom did say, and it was reported in msm that it was supposed to be a Girl's Night Out, so I think it's something to consider: Was Christina misled about the evening?
I think we are all brainstorming here, and I don't see why bringing up a topic is considered silly.