I have no idea were it came from...
the body is small , arms at full length range from 5-6" , a little color change he is lighter
from what you see in the pic, he is light brown to dark , i don't think aculeatus because i had
one that died and it doesn't look like it at all , also the skin is different , it looks generally diffrent
and behavior is different.
Clearer close-up pictures of just the mantle (top an side) could help, as who knows- it could be something totally different from elsewhere in the world. But those octos in the link you sent all look like they could be in Abdopus. This is a diverse group, and probably many non-aculeatus show up in the trade, so I wouldn't expect a perfect match. If the star-like pattern isn't there, then it could be nearing senescence. Given how smooth the skin looks this is possible. Do you see any skin projections (papillae)?