To recreate:

1) Place a Piston (or sticky piston)

2)Place a Redstone Torch on top of it

3)Place another torch, but on a block next to it

Issue:

The RT on the ground is powering the piston, but then this extended piston acts as a sort of powered block because the RT on top gets turned off.

It isn't just a visual glitch, because if you place i.e. another piston right next to this powered torch, the piston won't activate, so it is really getting powered by the top face of the piston below.

I tried with other blocks, like pistons, dispensers, droppers, lamps, but nothing seems to get powered, except for the torch.

This could either be a bug or a super-duper feature.