I volunteered to test the first two Doom maps of a forum user called Badboy. These maps fucking suck.
There is a noticeable cut and change of quality near the end. On my first try the map was broken at that point and the mapper had to fix some things so I could continue. I replayed the map and continued the video from there, but my original video wouldn't render and crashed in my usual program. I had to re-render the footage to avoid codec problems and that's why it looks like that.
Mouselook was forced by the map, and I didn't want to go into the menu during recording, so I tried to minimize its use as much as possible.