When swinging a tool in the main hand such as a pickaxe or sword while holding a loaded crossbow in the off hand the third person swinging animation for the player character will not play. The player will remain mostly locked into the stance for holding the crossbow and the main hand will slightly twitch in an odd direction when used instead of actually swinging the main hand tool.

This would look especially odd to other players and makes a player holding the crossbow's actions unclear when they're actively using their main hand tool. 

(Note that the first person animation does display correctly. This is just the third person animation.)