i doubt he knew what the noise was , he probably just figured since he can't tell what it was it would be better to leave, chances are he will be back . but he might be a little warier for the next few days. if you can, skip this spot for a week and hunt some other. maybe see if you can get closer to where he is coming from ,ie BED, so you can get a chance at him before it gets too dark
also he is probably not the only buck around and who knows maybe you will see his daddy from your stand