I have already mentioned this in another thread but... Yeah. That was for suggestions not problems so...
When shooting at an obstacle near you it will displace you from the map. This displacement does not reset until the round is reset.
Notes:
You can't see any hud models.
You can't shoot in any meaningful direction (presumably the particles is generated from the point the game believes you are at).
Mapmodels turn black if you shoot while near them (methinks it is linked to the particle lighting).
Screenshots:

^Variables

^Alt-shot at wall from a distance.

^As close to the wall as possible.

^Alt- is fired...

^Alt- is fired after respawn. The particles is not visible.

^Particle also does not cause an explosion when it should have collided with map geometry.

^Grenade^_^...

^...when thrown is also not visible...

^Normal mapmodel lighting.

^Lighting after alt- is fired.

^Bots also get discoloured (similarly to when the flag in ctf falls outside the map)

^From previous attempt at replicating the results.
So...
Why?