Hm, I don't have any trouble with the O rings. I do pinch the whole light when pressing the button, but I have always done that for all my lights, even the ones that were bolted hard to the bars. It's just part of the "be as gentle as possible to your equipment" method that my dad imparted to me back when I was growing up on the farm and we had absolutely NO money to replace anything that got broken. Holding the whole light and then squeezing to press a button, rather than just jabbing at it, is far less likely to break a mount. Same for computers, etc.