So this bug occurred on two separate occasions, once in solo Campaign and the other in co-op Campaign:
I attempted to solo Delta Halo on Legendary with every skull but Bandana, Assassin, and Blind. Right before I activated the checkpoint “Off the Rock, Through the Bush, Nothing But Jackal”, I noticed a drop in frames (probably 60fps down to 35fps), but it went away after a few seconds after I killed an Elite on the other side of the gorge. The AI decided to remain stationary while I was shooting him. When I reloaded the sniper rifle, it showed the actual rifle being titled to the right, but the hand that slots in the new clip didn’t show. I fired off a shot and reloaded again, but the hand was still missing.
This same issue happened again in co-op, with the same skulls activated, with the same frame drop outside of the same checkpoint. The only difference was a different weapon was used. I used the sniper rifle, my friend used a Battle Rifle. Both out animations are broken, and it remained as such for the duration of the game until we eventually saved and quit.
I have never seen a broken animation in Halo, let alone a broken reload. Anyone else bear witness to this?
NOTE: The Halo 2 Anniversary graphics were on at the time of occurrence.