Attacking in crawling is always the right hand, even if the main hand is left

 When you attack while crawling/swimming you always look like your are attacking with the right hand even if your main hand is left, which can be seen in the pictures. This also seems to not be client side as another player could see it too.

 

How to reproduce:

1. Set your main hand to left
2. Crawl/swim
3. Go to third person view
4. Left click(attack) while crawling/swimming