Wow, i am glad i didnt send the btc back I got paid double.

Freaking scammer
you got 8.4 btc by api mistake. you don`t want to send it to op!
and you claim op as scammer?!!I dont think blockchain API is at fault. They handle millions or $ each day.
Shitty script by OP is. He should refund you guys from the fee he took.
The API caused the issue with the addresses. Then the script screwed up with the manually entered addresses. This is my understanding from watching it last night.