http://www.youtube.com/watch?v=Fd51XRSQyM0
It's totally normal man! Look at this guy, he gets it all the time! Jk but watch it anyway his videos are hilarious!
To get back to your point, I never heard of a girl getting orgasms just by eye contact! However, I have seen a girl orgasm in the gym while doing abs workout! When I told some friends about it, they said they have seen a girl orgasm in a yoga class too!
Also, one time I saw a study out there somewhere in china they are taught to not feel pain and last forever in bed! So I'm guessing it's all in the head! If they can last forever, then they can last for few seconds too! There are always exception to situations like that, and you might just be lucky to witness one! It is related to the mind power, all the adrenaline and fast blood pumping running in her body!