Was she the catalyst to a suicide?

An acquaintance had a grandson age 15 who was unhappy and not very popular, who was befriended online by a popular and attractive girl in his school. She would post to his Facebook about how she thought he was cute and cool and stuff like that. He posted back and she acted as if she really liked him and that they might become an item. When he got bold enough to approach her in the real world to ask her out she clowned him in front of everyone. She told him that she was joking and she never liked him, that he was a loser and should go hang himself. He was so destroyed and humiliated he hung himself that evening to be discovered by his parent; it was too late to try to revive him. Was she the catalyst of the young man hanging himself? Would he have done it anyhow if he was unhappy? Did the young lady do anything that she could be punished for, legally or civilly? The fact that she said in front of many witnesses that he should go hang himself and he did, because she was nowhere around when he hung himself, or provided any means to do it, she gets off Scot free? What do you think?