Blowing up EnderCrystal using a piston during dragon respawning causes incomplete end portal

How to reproduce

1. Kill the EnderDragon one time
2. Place the EnderCrystals to respawn the EnderDragon
3. While they are preparing the fight, cause one EnderCrystal to blow up by trying to push it with a piston

Now only on the opposite side of the piston the portal was generated