Did they provide any information in the version/build/date of the release for the version they were playing?
As far as I know, no, but it seemed to be a very old version.
Yes, it was Desinc with the old version.
EP2 doesn’t have an old engine patch with bhop, as far as I could tell Desinc’s ep2 video could’ve been made with any version. EP1 has a weird old engine patch with bhop but with new engine style propflying, which is a bit hard to get. It’s probably the slowest version of source engine ever made so I dont think anyone would be interested in that.
If you mean ABH with bhop(the backwards jumping glitch), you can do it on the current steam version. If that is what you are trying to do, a common mistake that people make is holding S while jumping backwards.
Apparently the HL2 video was made using build 2707 which is available here:
You may also be interested in Blamod:
there u go, enjoy
Blamod is so buggy I can’t progress past Point Insertion.