One of my employees had this problem. Apple was very good about taking care of it. You just have to be prepared to be without your phone while its out for repair. The other choice is they will rent you an iPhone so you don't have to be without one, it's $30 plus shipping. He did not rent one as he is a phone enthusiast like myself and has other phones and lines to use when one is down. All things taken into consideration they fixed it and turned it around in just 8 days. Not bad considering how busy they are at this time of year.
Do you mean flush on the top or the side? I was referring to the side, it seems flush on top. From what I can feel I don't see anything getting in there and I don't think it's enough to catch on anything.