Clearly one of the more hilarious videos we've seen from you guys in a while. Death by Trooper seems pretty common, as is friendly fire (even if it's vicarious and/or non-fatal, such as by shooting an Exploda-BoB such that it blows up next to your friend, which did actually happen at one point) and suicide. Blackstar also seems to be on the receiving end of a lot of the killing.
Also, at one point, Narcogen pointed out blood stains on the ceiling. Those are actually scenery items, which seem to have been accidentally placed on the ceiling (an easy mistake; all it takes is someone accidentally toggling the 'From Ceiling' button or forgetting to turn it off after placing other items from the ceiling).
Lastly, and I should've pointed this out long ago, but I believe the reason for the weird weapon animation behavior you guys have been having is that you may be running another plugin that relates to weapon graphics. The one that pops into my head most immediately is Muzzle Flash and Motion Blur, which would certainly cause interference. Check that you guys aren't using that plugin, and if you are, turn it off - that should fix the problem.
Vale,
Perseus