“It really doesn’t sound like Pikuach Nefesh here. But there are ways to help someone without actually making physical contact. I would think that a bocher’s first thought is that he should avoid associating with a girl in ANY way, and you saying that there were a bunch of boys there, I would think that they felt their friends would make jokes about helping a girl, that should actually be able to get up by herself.”
No, it doesn’t sound like pikuach nefesh, but it does sound like the girl was genuinely in need of help and seriously embarrassed when no one offered to help her. The Gemara says that someone who embarrasses another person is as if he killed him. Public embarrassment is a serious matter. It sounds like you are saying that the boys were embarrassed to help this girl because they feared their friends would make fun of them. I think somebody needed to take a stand and help her. Better they be embarrassed in front of their friends who know them well and really are just kidding around than for her to be embarrassed in front of a bunch of strangers. Plus, who says they would have made fun of him? Her embarrassment is a known quantity; his is hypothetical. I am sure she was physically CAPABLE of getting up by herself and found some way to do it, but she was struggling and helping her would have been the right thing to do. No shomer negiah violation was even necessary.