No one really knows what happened because no one who was there has said anything but Nico and we all know Nico loved to lie. This is what i have heard.
Nico was drinking a beer at a Mexican restaurant when these two black girls came in who knew the Black Panthers. One of them kept saying, "oh how we people have suffered! You white people don't know what suffering is!" And for Nico, someone who grew up IN World War 2 and saw death and killing at a young age, had a father who wanted nothing to do with her, got pregnant by a man who wanted nothing do to with her, etc. She felt that she had suffered plenty. So she yelled, "you don't know what suffering is!" and threw her berr at the lady. Some people say Nico then went up to the lady and started grinding the glass into the ladies face, but i don't know if that part is true. So Nico felt she had to leave the country or the Black Panthers might kill her.