Well, I had written this long, detailed response, and when I hit "post" it disappeared, so I will try my best to retype it from memory: Sounds to me like inexperience, immaturity and naivete are to blame -- maybe also some low self-esteem. She is still in love with him and is probably hoping he will see the light and go back with her if he notices how much she is willing to do for him. I know I was guilty of the same behavior, around that age. I wanted to impress this guy and became a pushover, someone he could walk all over. I was hoping my actions would eventually get him to want to be with me, because I was just so smitten with him! I tolerated being stood up on dates a few times, him taking me somewhere where his ex-girlfriend would be and holding my hand, just to make her jealous (he even admitted it and I didn't see any problem with that back then), stayed up late burning music CDs for him -- all in an effort to get him to stop being aloof and noticing that I was so dedicated to him, that no one else would do all the things I did for him.
Sure, he could be charming, one time he offered to get in the face of my college roommates who were tormenting me (which meant driving almost 2 hours, just for me, oh, how chivalrous!), but, most of the time it seemed like he just enjoyed the flattering he received from my company, the fact his friends admired how an awkward, short, geeky guy could get an attractive woman to like him, the compliments I gave him, and the fact I bent over backwards for him -- all while he had the luxury of sometimes jerking me around. I had an on-off friendship with this guy for a couple of years, hoping he would someday be my boyfriend, despite my mother's advice that he was using me and that I was too good for him, because I just loved a self-assured, highly intelligent guy. I didn't know about things like manipulation, I was naive and inexperienced when it came to relationships and I thought she just didn't like him because that's what moms do. One day, it just clicked, and I was done with him for good, never sought him out again.
Young men and women can get very attached to someone (yes, I now admit I was guilty of that, being a clingy person). They can become obsessive, especially when that one person was their first true love or serious relationship, I would say. I don't think she realizes that most people simply do not change, and a guy letting her take the fall for something he did to the point she can get in a lot of legal trouble is a user. To me it shows he doesn't give a hoot for her. She probably has been watching too many romantic movies where the guy suddenly realized the girl doing everything for him was his true love, he wakes up, apologizes for being so stupid and blind, asks her to marry him, and they live happily ever after. In real life, people like that take advantage of the vulnerable person and drain their blood as much as they can, it's not like in the movies!
I think part of the reason I put up with this was because I suffered from low self-esteem as my parents were always on my case about my weight, and I guess I enjoyed the attention from this man, however bad it was. I was also very socially awkward when it came to relationships and very inexperienced, so I never thought this guy was full of red flags, though I certainly can see it now. At one point, when younger, I thought a guy controlling me meant he wanted me in his life, and was romantic, now, the minute I feel anyone trying to control me, I am out. This may be what is going on with your daughter, as well as a fear of being alone, and not knowing how to stand on her own two feet, without a boyfriend. For many college kids, their relationships and love life define them. Maturity and life experiences change things. Maybe this punishment she faces and his shrugging and unwillingness to come clean and man up may be the slap in the face that she needs to wake up and realize this guy is not good news, he is a manipulator, and that this isn't a healthy relationship.