I checked my cw9 and mine does not have a dent like yours. If it functions ok then it probably will never cause a problem, still it should not be there. I think I would contact Kahr and send the photo and see what they have to say. The cw9 is fun to shoot and very easy for concealed carry. Good luck.
"Convincing isn't what we do. We deal in lead."- Roland of Gilead, the last Gunslinger.