I found something odd in the first version of TF2, (1.0.0.0, from the 17th/18th of Semptember, 2007,) It's a small .dmx that's only 322KB in size. It's called "medic_lowendface.dmx". It's an HWM Medic moving certain parts of his face, then going back to his default position. Nothing else moves, only his face.. The model itself is messed up, his torso and everything for that matter, is grotesquely bent, arms bent in the wrong directions, etc., while the actual bones are in their normal places.
I made a video about it.
https://www.youtube.com/watch?v=tA-Dm0r-mO4
(There was no map, so I loaded in "stage.bsp".)