I don't think his hand should look like this
It looks fine upon more inspection. If you were holding an object oriented in that manner, your hands would look the same. The only difference is that Kane's palms are huge for that avatar which makes you believe it's not okay. But it's fine.
Clarification: his wrist has zero thickness when hand rotated to this position
yup, it looks like the hand just simply disappeared.
Okay, thank you for clarifying.