I started a new project on my creative world, when I was breaking bedrock and pistons, I noticed: the block nearby may break even if I don't destroy it.
I know I can't really explain myself better, so here is a GIF: https://gfycat.com/TenseBlushingAsianwaterbuffalo
P.S.: Sorry for uploading it on gfycat... The max file size is 10 MB here...