I am saying that ultimately the study asks the wrong question. It is meant to refute the common religious notion that the non-religious are immoral and therefore violent. I agree in principle that that claim needs refuting, but I would never use the same evidence as they do.
Instead, a better, more interesting question would be to approach it from a different way; start with the premise that humanity exhibits violent behaviour by default, regardless of religious worldview, and then have a discussion on the parameters of that violence; when, why, by whom, under what circumstances, when is it accepted, lamented, honoured, exalted, etc. That's much more fascinating, and (in theory) avoids a moralistic apologist stance.
But to answer your specific question:
<<Are you saying that religions are all equal, and don't lay out any specific moral commands?>>
I am saying that the specific moral commands are easily and continuously adjusted and interpreted according to a variety of factors.
For example, there is a common fallacy that Buddhism is non-violent. This is a claim made by people (usually Westerners with a fetish for romanticizing foreign ideas) who have never actually looked at its history.
Perhaps it is because I am a scholar of religion, and can no longer actually see morality - religions are neither "good" or "bad" to me, but actually rather neutral. I am look at them in terms of how they function in the great machination of human history.
I judge them personally only in terms of how and when they affect me personally, or offend my sensibility, but can easily (at this point) compartmentalize those feelings in order to view history as a whole as an amorphous blob that moves along slowly, and the more I do that, the more I begin to recognize threads of thought that weave in and out of each other over the ages, completely ambivalent to my feelings.
I have not been outraged in a long, long time.
Oh, but that South Park episode was fucking funny! It was exactly what I was thinking about when I made the reference.