No - It isn't.
Kid was dressed like a typical OWS Black Bloc protester (No Nads, they really aren't separate - Black Block has become OWS military arm, and operates such that they give the rest of OWS plausible deniability) engaged in attacking those who are supporting a film made in part by a known 1% conservative, Chuck Dixon.
So, Nads... Using your "stochastic terrorist" theory, OWS is just as likely to be responsible for this as any conservative you mention -perhaps even moreso.
Holmes was an OWS sympathizer, and indeed a "Black Bloc" Anarchist.
As you say, if he was indeed a "Stochastic terrorist," then the ones to blame are the OWS activists that openly call for violence, lawlessness, and acts of terrorism on a regular basis (Then act all shocked and deny any involvement whenever some nutcase like Holmes actually does what the activist was encouraging), not any of the conservative media pundits that the DUmmies randomly blame for acts of domestic terrorism with no proof.
btw, Chuck Dixon's a conservative? SWEET! I met him at a comic convention a few years ago and got his autograph!