I'm sure about it though. I watched the video in slow motion and I took this pic. It shows ermac hit Kabal (I think) unmasked. You can see he is holding his hookswords. Please correct me if I'm wrong, it is very hard to see.
He could be he couldn't be. I'm playing the video and as far as I can tell he has his mask on, and then at the end (what you posted) it looks like a human face (and god, I sure hope that's not his human face).