Steps to reproduce:

1. tame a wolf
2. build a constrainment where the wolf will pass by your crosshair while you mining (e.g. 3x1x2 room with window) and put wolf in
3. bait wolf to pass by your view in same time while you breaking block
4. you would see that crosshair focus have been passively switched to the wolf, and previous block-breaking state remains in freeze until you interact with

Didn't tested with other entities. I scared that would be not about breaking animation but internal breaking state and evolve some block-break exploits, please check it.