Hey, guy, before you go claiming I'm a liar: *Gasp* What's this? A demo?
Have fun with this, Staff. I know I am. The infraction - the one that got recorded, anyway - takes place in the last few seconds of the demo. Just as Yimbo gets to 'nade level, he chucks his 'nade on-screen and immediately suicides while on the ground - not a fall to his death from above - in order to respawn with a new un-earned 'nade.
Edit: Whoops. Slight inconvenience, but I recorded two demos with the same name while trying to catch this guy. It should be the 'second' one, yimbo3_2, but there's a chance it's the other one so I've attached them both. Either way only the end needs to be checked. I'd check them myself but I lack the software and/or knowledge to do so.
Edit 2: My mistake. Subject is not necessarily connected with MiStIk*. I misread a ban appeal thread and thought two SteamIDs matched that do not in fact match. I apologize, and have edited this post to remove the incorrect information.