So since there doesn't seem to be any public information on this bug yet I think I'd post it so I don't have to explain it again. I discovered it randomly a few months ago and thanks to Shadowplay I could recreate it.
This is the strategy I'm talking about (5m30):
1. Hug the corner so that your horizontal velocity is zero
2. Release all movement buttons
3. Look at the right angle (2nd angle on cl_showpos)
4. Press A or D to strafe
into the wall
These are the angles that work:
(+/-)24.26
(+/-)114.26
(+/-)65.70
(+/-)155.70
Seems to be quite lenient, approximately ?0.1 angle leniency it seems.
Additional information:
- Only works on walls you can get randomly stuck on (func_brush, func_button, etc.)
- Is not 100% consistent, sometimes you don't get stuck in the wall