Did anyone else notice this Scream 2 fail?

Ok so im watching Scream 2 for like the one hundreth time and i noticed something. In the scene where dewey is getting attacked. He yells into the microphone and gale turns around. When she screams and pounds on the glass, you see ghostface's reflection in the mirror. Its just his mask moving slightly slowly, to the left. And there is no dewey reflection. And ghostface is supposed to be violently cuting dewey, not moving slightly to the left. LOL did anyone else notice that?! Sorry for spelling and grammer, its hard to type on an ipod