International Institute of Cricket Umpiring & Scoring
Batsman is recalled
"We were involved in club friendly match and it was obvious that a lot of the players hadn't played the game for
years - if ever!
One of these players, while batting, was hit by a delivery on the forearm just above the glove. The ball was then caught in the slips. Someone appealed. The batsman promptly walked off, believing he was out. The umpire called him back. Is the umpire allowed to do this? I thought it was only a captain who could withdraw an appeal?"
If he was hit on the arm, above the glove, he wasn't out anyway!
Captains can, indeed, request the consent of the relevant umpire to withdraw an appeal. But umpires have a duty to stop a batsman walking if, as the Law says, he's doing so 'under the misapprehension' that he's out.
Read more about Law 6.8 (The bat) and Law 32 (Caught) and Law 27.7 (Appeals) at the MCC website