Quick Flash In E3 Video

[IonizeMyAtoms]

While I'm 99% sure this has been discussed before, a quick search brought up either too little or too much, so I figured I'd just ask.
In the 25 minute FilePlanet E3 video, just after the second Ravenholm portion (after the player lights some zombies on fire), the screen goes dark, then quickly flashes. This happens at 20:40. The health is different than the sequence that preceeded it, but I can't find anything of interest.
Any help?

 

[CTTcrew_MrBlue]

you can see that scene and more if you watch the ravenholm bink.