very poor quality control imo
no. it is not a "quality control". they are designed this way. as i mentioned, promotional photos of all preds already have this mixup. though a sculptor for sure thought about the right way.
can the upper arms be removed and swapped into correct place?
sure. the biceps are made from 2 parts, glued together, with holes holding elbow and shoulder.
if you manage to insert a knife, for example, into a junction, you can divide a bicep into 2 parts. better to do it from backside - it is black there and has complex texture, and if you damage plastic a little, it won't be so terrible like if you scratch the light, smooth front side.
then you have 4 parts for 2 hands, change places (putting elbow and shoulder joints back), glue the parts together (trying not to place glue to the joint holes) - and here it is.
better begin reassembling from the elbow side, not from the shoulder. because you can completely remove the elbow before operating - and get an empty hole where you can easily place a knife.
i did it with P2 and broke nothing.
p.s. one more detail: P2 had some sort of soft resin glue inside biceps on elbow/shoulder joint places. do not remove it! they make joint movement strong.
and... if it doesn't bother you too much, better don't try. or try it when P1 is still cheap enough
or the best way - find out that 1/6 predator 1 body on ebay goes around $40-60 today, get one and make experiments
Buy It Now Price: US $56.99
p.s. actually i didn't
notice biceps mixup. simply reassembled them to make the shoulder joints stronger - and then looked at 2 forearms and tried to guess, where is right and left. tried to change position - and liked it much better