set the height of the sprites to a negative number at the time when they're messing up, and back to a positive when they're in the "non-messed up orientation", it'll flip the arms vertically, fixing the problem i suspect. didn't try it since i cant open your cap for wtv reason, but see if it works.
I'm not sure that's the problem, here's an image of what's happening:
So when facing right the two arm sprites are bending correctly, facing left they bend out the other way, the images are also flipped but your solution fixes that.
lol, the game looks better than that drawing