If the wind was from the north and he approached from the south, then he winded you. I ground hunt all the time and I've had it done to me too. Best thing I can tell you is set up to hunt into the wind. I.E. Stay downwind of the area you supect they are bedding in in the afternoon. Or downwind of the feeding areas in the morning. But always keep a shooting lane open behind you in case the Big One slips in behind you to catch your scent. Good Luck.

KEEP IT LEGAL. KEEP IT SAFE. OR WE MAY NOT GET TO KEEP IT AT ALL.