When Manny is about to enter the greenhouse again after he sproutella-ed the pipelines and Hector dies. The doors open a little. Then you see the shot of Manny, from a low camera, throwing down his gun and turning around/walking away.

This looks extremely simular to Marshal James Anderson's same move after he kills the Sawmill's endboss in Outlaws.

I'll get some screenshots later today. First gonna take a shower. :p

I kinda thought that was from a movie too. But then, Lucasarts always have their in-jokes.

Actually, it's quite a common dramtic effect in movies. I just saw it this morning in fact, in a B-grade made-for-TV action flick. One guy caps another guy, throws the gun away. A move usually executed by a character that doesn't carry a gun of his own.

Or by people like Neo, who just have too many damned guns. No time to reload, just drop the gun and grab another! Jackass... totally irresponsable. I mean, the baddies in Die Hard with a Vengeance, at least they were responsiable: "suppose a kid finds it??"