In this case, I highly doubt Islam has any relation whatsoever to the person who committed the act. However, you'll find that I'm actually quite the critic of Islam - for the reasons you've stated. I'm not an apologist for the religion, and I do feel on an international rather than America-centric scale Islam is one of the greatest purveyors of this kind of violent behavior.
While if a Christian follows the bible the way they are intended to (as in, Leviticus does not apply because the new covenant is for all people and is not meant to continue the specific cultural laws of the Judean tribe of the Israeli people) these "evil bible quotes" actually aren't meant to apply to Christians (and ones that do, such as when it uses the word "homosexual," the actual word used likely refers to some form of male prostitution and not homosexuality) - the Qu'ran is intended word for word to be taken as it is written, and it does call for the killing of nonbelievers... and calls for the punishment of apostasy to be death.
The "moderate Muslims" are simply the ones who choose not to follow that their religion tells them to, because their conscience outweighs to them what their religion says they should do (as in, they're "bad" Muslims). I am not a fan of Islam, I do not see it as a religion of peace by any means. Though to be very clear - I recognize that the vast majority of Muslims are "bad Muslims" in this sense, which is a good thing - and I have a great deal of respect for many Muslims and have found the ones I've known or interacted with to be spectacular individuals (and yes, I do personally know and greatly respect those muslims). So I'm not some kind of ethnocentric Muslim-hater as some are, quite the opposite - my critiques are of Islam itself, and actually does not apply to the very vast majority of muslims - who are usually more devout to God and more loving and peaceful than most Christians I meet. So in no way am I attacking the Islamic peoples, just the heart of the religion itself.
I'm a big fan of ideological consistency (such as, taxing cigarettes heavily for bad health effects yet not doing so with red meat, the other major cause of heart disease, is nonsensically hypocritical), and for me this falls within that.
I mean this with no disrespect to muslims, and like I said, most are far more holy than most Christians - and I don't (as a Christian) see Christianity as the "best religion" or "superior." But in the unique case of Islam, yes, I think it (as a belief system) is responsible of the same kind of thing that I'm accusing the American right of.
However, it is reforming in some places, and hope it continues to do so... it can otherwise be a wonderfully positive influence on peoples lives - I'd like to see that aspect of it become dominant.
Well, I'm not exactly known for an anti-Muslim bias.
But, I think it is wrong to lump all Muslims in with the group that burnt the effigy. Likewise, I think it wrong to lump all conservatives in with one guy who hung a chair.