generally when you have a big ol buck that close, grunting will do just that, scare the heck out of em! he knows there isn't a buck there and at this time of year he will be very reluctant to investigate, especially seeing how he was soo close to where the grunt erupted from!! i don't know what to tell you as far as whether he will return, depends on what this area is to him, bedding.....or if he was using it as a travel route......he may just alter his route a short ways....but not far i would imagine. good luck!