Oh really? So highly collectivist cultures are more prone to forgive cheating (which is really just a form of rule breaking) than individualistic ones? I'd like to know how that accords with the canings meted out in Singapore for littering, or the execution of public officials for taking bribes in China, or the public stoning of those quite literally caught cheating in Taliban Afghanistan.
Moreover, Americans forgive cheaters all the time (although we're not as blaise about it as much of Europe) such as Tiger Woods and even Bill Clinton, leader of the US, not only cheated, but LIED about it and received basically a slap on the wrist. I will agree that there may be a tendency amongst self-identified 'religious' Americans to think they're morally superior, but I highly doubt that there's a large actual difference.
If you've some links to the relevant research you didn't cite, I'd love to see them.