Digging bugs in redstone circuit

Steps to reproduce:

1. Place 2 blocks next to each other, with redstone dust on the top.
2. Place a sticky piston next to the block
3. Place a block of redstone on the top of the sticky piston

Phenomenon:

1. When you try to break the block of redstone in a side view, it doesn't work.
2. When you try to break the block of redstone in a bird view, the sticky piston breaks.

Expected Results:

I don't need to say. It's easy to understand. You may watch the video first.