Why was this figure made with 2 right arms?
 

If you look up "2001 Mattel Dumbledore" You can see how this weird figure was made with 2 right arms. It was intentional, not a one-off defect.

“The intention, according to Mattel, was that the left arm was to be raised above Dumbledore's head and would look like a right arm in this position.”

It's clearly a cost cutting measure but can anyone who knows more about toy production help me theorize how/when during the production process would they have decided to reuse the arm mold?

Did they make the torso mold, then a mold for the right arm, and realize the arm mold could be reused? Or would it have been planned that way from the start? Thanks for any ideas.

I do believe this was just a massive bone headed oversight on their part. The artist just didn't do his job properly