...so, what you're telling me is that if I take out a line of code that reverses how the centre-of-mass to lab frame transformation is done, I won't get the right angular distributions? huh. And that if I don't realize that this is what I've done, I'll waste several days debugging? huh.
I've said it before and I'll no doubt say it again: Life would be a whole lot easier if I were just a bit smarter.