Even though the pin is on the right side of grip, it still could have started out being drilled for a lefty, using longer pin-to-pap distance.

The only other reason I can think of would be to add in positive side weight to bring it back to legal. There are a few things could have led to that: mismarked CG (this is why you always check every ball, even those that aren't blems), swinging the theoretical mass bias into the track area with a long pin-out, careless driller who wasn't watching where the CG was, or who really knows.

The weighthole placement on that ball, in and of itself, isn't all that exciting. It's certainly out of the ordinary, but so long as it's on the negative-axis-point, it shouldn't significantly effect ball reaction and serves no other purpose than to bring the ball back to legal.