According to this picture, Reiko (the girl on the right) has two right hands. Bear with me as i explain.
I can reach into my left back pocket with my right hand and vice versa, so Reiko pulling her side-tie bikini string with her opposite hand from across her back is still plausible. However, that hand holding the side-tie is supposed to be Rika's (the girl on the left)... because Reiko's right hand is caressing Rika's head, since we can see that the thumb on the hand on top of Rika's head is on the forward side (if Rika's caressing her own head, then the thumb should be on the backward side). So... should it be Rika's hand holding Reiko's side-tie? Yes, apparently so... but the angle of the upper arm is drawn wrong, since it should be coming at a lower, almost horizontal angle. Such upper arm placement in this picture is absent, instead Tony drawn the upper arm of the hand holding Reiko's side-tie at an almost vertical angle, suggesting that Reiko is holding her side-tie herself... which is impossible.
So yeah, even Tony makes weird (essentially logical) mistakes sometimes. Tagging it bad_hands.
Ok, it looks like the hand holding the black bikini was supposed to belong to the girl on the left, at least when he started drawing the hand. Because the hand on the left girls head looks like it belongs to the girl on the right.
Technically, I guess it's the arm that's wrong... He must work a lot zoomed in/staring closely to do this so often.
