Deadspace 3 Co-op bug after Nexus boss fight

So my friend and I beat the Nexus boss and got to the QTE where Isaac has to kill Norton. The problem is, my friend completes the QTE and kills Norton, but on my screen Norton kills Isaac and then it just stays there. Isaac remains dead and there's no game over or anything. It just shows Isaac dead forever. My friends game then freezes up after the movie completes. We tried restarting a couple times with no success. So, what's the deal?