I’m having issues with the “crate smashing room” in Unforeseen Consequences. Beyond it being the most difficult part in the game for me (it was in the original HL too), the issue I’m having is with the purple hat.
If you’re holding the hat while quicksaving on the slowly swinging crates (I do a lot of quicksaving in this part), Gordon will drop the hat, invariably falling off the crates and down into the canals of death.
Gordon will apparently not drop the hat while standing on anything else, but I haven’t gotten far enough to check to see if it’ll happen on elevators that actually move.