Steve442:
As the shot seems to be dead centre of the hole I think it may well have dropped. You should always pull the flag.
No offense but IMO you shouldn't always pull the flagstick. There are some holes such as on Bethpage. Oakmont, Olymplic etc. that have severe down slopes coming out of the rough if your ball lands on the wrong side of the hole. In these cases hitting the flagstick can possibly aid preventing the ball from rolling a very long way from the hole if not hit perfect but I agree with you in most cases it is better to have it pulled. IMO one just has to look at what they are faced with and make the decision to pull it or not based on that.