Unable to destroy the piston flag.

This issue can impossibly affect 1.7.10, because banners were not in the game back then. Also, this is working as intended as being able to push a block with a piston has to be manually activated by the developers.

Yea!

the banner is a tile entity, they simply cnnot be moved

He must be destroyed and be subject!

2 tings:
1 it's two blocks high
2 it's a tile entity
both disallow it to be moved, intended behaviour