Bug of Bow in Minecraft Shapshot 15w43c

Bug of Bow

When I have the bow in primary hand (hand on the right) to work normally, but when I step off-hand (hand on the left), when I want to shoot the animation of the bow is not as it should be . Briefly, the bow works perfectly but the animation is wrong.

Details (IMPORTANT):

The character is set to the right hand is the leading hand and left hand, the high hand.

The bow works perfectly, but no animation.

In the picture I show you what I mean.