Anyone else ever have this happen?

I was playing as an assassin and after grappling somebody, I was frozen. Well, sort of. I could still attack and use abilities, but I couldn't move, just run in place. I could be knocked around by bot attacks though. I also could not die. The other players shot me with everything they had, even tried to grapple me, and it would not deal damage. My health was permanently at zero. So I just sat there in front of their bot spawn pumping shurukins into it.

It was pretty funny but uh, yeah, fairly sure this isn't supposed to happen >.>