So what if Moderate Muslims assure us Saipov was acting out-of-faith. That's irrelevant to the irreversible outcomes.
It's a distraction to claim, as The Moderates do, that the Jihadi is misinterpreting Islam, and that we must all do battle for the real Islam, a thing as elusive as bigfoot or the unicorn. Fact: A Muslim's actions, be they in accordance with the real Islam or not—sanctioned theologically or not—could be deadly.
Proposition 1: The faith of all Muslims is Islam.
Proposition 2: Islam teaches and sanctions some disturbing things like Jihad against the infidel.
Proposition 3: Some Muslims, practitioners of Islam, will be prone to act on teachings that are indisputably part of Islam.