Pretty sure the left back leg came off of both of my griffins as soon as I took them out of the package and started freeing up the joints. I know for sure it happened with the one I bought when the customer service stock went up for sale (i.e. the second one). I just pushed it back in there really well and it seems to be holding, but I don't play around with it much. Pretty sure it'll just pop off again if I apply enough pressure, so I won't do that.
I'm just happy the paint stayed on the wings of that one, unlike my first one.