Demo
http://www.mediafire.com/?7x4jh5wefcbk0z0 It's quite long as it is the whole map. I will highlight the rounds of interest to save you all time. Please use the command viewdemo [demoname] on console to get access to the time bar and skip to the relevant rounds.
Spectated in round 16, ticker timer 18:40, seen to be walltracing. Suspicions raised.
In round 21 spectated again, ticker timer 25:10, appears to be wall scanning and with minimal sound cues waits on a very strange angle for an awp shot.
Again in round 22 at ticker timer 26:20 and 26:30 quite blatent wall scanning, sound ques are much closer than he's seen to be looking.
At this point I'd seen enough to be confident in my own mind he was wallhacking and enforced a ban.