Defining the perpetrator when dealing with Anonymous is... odd. In a way, it's sort of a win-win scenario for them; basically it comes off as being that they are acting individually, together. If an individual deviates from the ultimatum, they are ostracized as not being involved, but aside from that, everyone is Anonymous.
To be perfectly honest, the only way to judge if it is "Anonymous" or a deviant is observational patterns. As the... spokesperson mentioned? Interesting. Anyways, as they mentioned, Anonymous supports free speech, as annoying as some of that speech is.
Though there may be an entire band of people devoted to trolling the hell out of WBC (Personally I'd "turn the other cheek" for such people), guising as Anonymous, and acting with the same tactics, the difference between Trolls and Anonymous is in goal.
If this wasn't something that the WBC just made as a guilt card (see: breaking your own toe), it's got the "Troll" feel. Anonymous is too busy trying to dig up dirt on big business types apposing WikiLeaks.