I found a bug where when you break a deadbush above dirt and then immediately (or as close as you can), the dirt partially breaks and does not return to its previous state. Occurs repetitively, and when the block (that is not a deadbush) it returns to its previous state. I only tried on grass and dirt, but I imagine it works on other blocks too.

Update (7:47PM PMT): When the dirt turned into grass it stopped staying partially broken

Also, I added the wrong image the first time.