What was he doing in the bushes? From very careful (and slightly drunken) analysis of the footage I can conclude only two things:
1) He is casting the 'imperious' spell and controlling Bush. Look closely at the muttering and the lack of blinking. Two requirements to effectively cast spells of control on someone. It must be a minor spell since I can't see any sacrificial creatures nearby...unless...oh no! What if the Iraq War is one giant source of unlimited power for the Dark Master???!!!??
2) He's a zombie. Note the drool and and fixation. The muttering looks a lot like 'braaaaaiiiiinnnsssss'.