Y'Know...
I haven't played L4D 2 yet, only L4D, but I'm at least 190% sure (and yes, I typed that correctly) that this is how Valve got their logo. Although as for it being in L4D, I assume Valve could see the future, got francis on a chopper over to the spot this was gonna happen, had him take the photo, and THAT's how they got the logo... oh yeah, and they had a time machine. |3
... Oh yeah, and this video was amazing, so 5/5, 10/10 for you, good sir. :D