When Christine and Raoul were on the roof Christine heard the Phantom say her name, did she forget he was there during the song or did she know and not care because Raoul made her feel safe?

She didn't know for sure if it was really Erik (the Phantom), as she said in the original cast recording, "What is that?" However, the comfort of Raoul's presence made her forget completely.

This is a scene that was even inconsistent in the book. In the anterior scene [book] Christine could hear Erik through the walls when she was trying to talk to Raoul in a adjacent room during the masquerade scene. But a few minutos later couldn't tell that he was following her to the roof? the argument can't even be made that she was just caught up in the moment with Raoul because she was with him before and could still hear Erik. So it just doesn't make since really.