I think the sex probably has little to do with it. The key is the alcohol and related conduct.
Notice that this attorney said that his client admitted to drinking. I'm not sure what the current penalty for that is, but in my day that was either a 5000 or 6000 level offense if committed on grounds. The attorney also claims that the girl "lied" about her drinking, which means she denied it. Now unless there is affirmative evidence to disprove that, the difference in the two cases may be he used alcohol, and she didn't.
With the drinking age at 21 now (unlike back in the day....), for a mid to drink underage is a conduct violation. And I suppose there's even a chance that he used a bogus I.D. or something to get it, which would be an honor offense.
In any case, I think the real issue here is likely to be the alcohol consumption and his apparantly rowdy behavior rather than their playing hide the salami. The defense attorney just spins it as being about sex because he's trying to claim that they engaged in the same conduct, i.e., sex, and so he deemphasizes the alcohol, and claims she "lied" about it. Apparantly, the evidence of her lying wasn't good enough.
I think you might be onto something, XJar, because otherwise the story doesn't make sense.
In my day, boozing in the Yard or illegally at the stadium would earn you a 5000 or 6000 offense, and if they caught you with a fake I.D., they could toss you for an honor offense as well. I had the unhappy job of sitting on such an honor board myself, and had to vote to kick out an otherwise stellar mid who had a brain cramp and used the world's worst attempt at a fake I.D. at Roerdon's . . . probably less than 400 yards from Gate 1.