Watching the movie the other night, it suddenly struck me that this was a very strange line to come from Starscream. Anyone else able to decipher the meaning? Is it meant to imply that Soundwave was playing double-agent, and the watch-con was actually an implement of Starscream, not Megatron?
I just took it that Sam getting information from Prime for Dylan to save Carly was, in general, "working for them". Or, he could just be referring to the fact that the Decepticons were going to enslave humanity, and Sam is included in that.
I don't understand what Soundwave has to do with anything. The line is trivially obvious. Starscream is mocking Sam for being complicit in the destruction of the Xantium. The watch wasn't an "extension" of Starscream. Decepticons = one faction. Sam was forced to work for them.