Could be that, since he didn't see the decoys, he got nervous and backed out. Don't assume that he didn't see you, just because you didn't see him though. They have some pretty sharp eyes...Might give you a clue if you go where you think he was and look back to where you were...Could you have been silhouetted maybe? Possible that his gobble was echoed off of some formation and sounded like he was somewhere where he wasn't? You know, you were looking in the wrong direction? I'm just throwing this stuff out there...