I don't believe he did. The ball went dashing back toward some other fans behind The Fan, not out onto the field. Which is another reason I believe the ball was so close to the stands that The Fan had a legitimate excuse for trying to grab it.
After the incident, when the camera went back to the sulking Fan sitting there looking glum, my first impression was that he looked so glum because he ended up not getting the ball. But then I heard that people were yelling obscenities at him and threatening to kill him, so I figured he quickly realized that he had really, REALLY screwed up.