I don't know any way this could be useful but it's still annoying to encounter bugs when fiddling with rails that already are weird sometimes.

Steps to reproduce:

1.  Place two solid blocks next to each other
2.  Place a piston on one of the facing the other
3.  Place a rail of any type i front of the piston
4.  Place a rail two to the side and one down like this:
5.  The power the piston and the rail magically floats like this: 

Expected behavior:

The bottom rail pops of or stays flat on the ground. 

Possible explanation:

The bottom rail connects to the floating rail before it pops of and doesn't get updated

Notes:

The images where taken with the optifine mod installed but I confirmed that this works exactly the same in vanilla.

Sorry for a ton of edits. 

Pleas let me know if there is any info missing.