grass bug

when i broke tall grass (in creative works in survival as well) if you break the bottom half of a 2 block tall plant it will turn into a peony for a millisecond then break

What I expected to happen was...:
it should have just broke

What actually happened was...:
it turned into a peony for a millisecond (only if you break the bottom half)

Steps to Reproduce:
1. plant or find a two block tall plant (any plant will do)
2. break the bottom half
3. then watch it is fast so look carefully