What I expected to happen was...:
The dripstone should fall and immediatly disapear. 

What actually happened was...:
The dripstone floated where it was placed.

Steps to Reproduce:
1. Make a command_block that kills everything every tick.
2. Place a dripstone on a celing.
3. Remove the block the dripstone hangs from.

EDIT: All falling blocks are affected.