Okay so I was playing Shutdown on Hslo 4 and the part when you first see the Promethians in this level, a Knight appeared next to a dead elite and the elite sort of crawled/was dragged off the platform and fell off. I’ve never seen that before so I assume that’s a glitch. It was really cool but I immediately thought of the flood controlling it. XD
Sounds like the Elite got stuck in an animation (probably diving)? That’s a regular occurrence in Halo 4.
In various parts of the Halo 4 campaign, you can find elites crawling/ dragging themselves but they usually collapse dead before getting too far. It may be preprogramed into the game, or it could just be a glitch.