While mining a block in adventure mode (using an appropriate tool) If you look away from the block you are mining and without letting go of the mouse look at another block that cannot be mined with that tool the damage graphic on the old block persists. If you look back at the block you started mining before the block will continue to be mined from that damaged state as if you never looked away.

the image below shows a damaged cobblestone that should have lost the damage associated with it when I looked at the wood. This only works in adventure mode with a tool that affects one block but not the other