That should probably get patched. cp_process_pro incoming.

Looks very similar to getting stuck on the power lines and shooting over the wall into spawn on Upward

This is an issue with the source engine and angled walls... there's not much you can do as far as I know.

This is a really well known bug in the jump community, it is called wallbugging, some people actually use it as strats for speedruns, so far it seems to happen randomly but some walls more than others, I don't know the actual cause.

The reason for this is, as Hyce said, angled walls.

Player collision doesn't play well with a lot of things in source, as you know if you've ever played on a custom map with moving platforms. This is caused by brushes which are not at a right angle to the y axis of the map; it isn't map specific, and cannot be (easily) replicated or fixed.

This isn't to be confused with getting stuck in displacements, which is a much more noticeable and repeatable problem caused by edges being left uncovered (ie in gullywash mid) and is inescapable without killbinding or noclip.

you can do this on the lighthouse in sunshine too

http://cloud-4.steampowered.com/ugc/36348118622187614/E027C1272B969893EC2288D72F955EF3E3731A41/

Could you create a clipbrush at a right angle to the y axis of the map and cover the non-right-angled wall with it? Might be missing the point, I'm not a mapper.

it happens with any stacked angled brushes, it's a precision issue so it's somewhat random
sometimes you land just right where you can downright stand on it
it can mostly be avoided with a fat clip, but that makes angled walls even more "fatter" than they should be

This bug is from Quake 1. People use it now and again.

If this for some reason becomes an issue and people want to fix it, you can make an angled brush non-sticky by turning it into an instance before you put it into the map. It would be a pain in the ass to do for all the angled brushes on process though.

Here's an explanation of sorts. Your suggestion, the tilde one, works to prevent the bug from happening. On maps like process, however, where the oblique walls are relatively large, the resulting clip brush is too large to be reasonable. The only other fix that I could think of also has an issue.

you can also clip with displacements but they have their own bundle of bugs

oops, got the axes wrong. i see now!

I never thought of using this that much like you did in Process for example, I've only just messed around with that trick in places like Badwater spawn but that's what I get for being boring and bad and never play Soldier or Demo.

How long would it take until someone would release a complete list and an album of all the maps and spots where this trick can be used?

Don't you only stick there for a short amount of time though? Can use it to avoid fall damage in some spots I've noticed but if you're only up there for a few seconds wont people see the roamer jumping up there anyway? Or is it possible to stay there longer by holding the right keys?

u literally cant fix this unless u remove every single angled wall or change the engine, neither of which will happen

is this considered an exploit as far as league play goes?

doubt it

it's too easy to do accidentally to punish people for it

if you hold the right keys you can stay up there for as long as you want

+left, +back
Go to loo
Come back and drop the medic
Sounds fun