Hoppers behave in a different way depending on the build sequence in this very specific case:

Here I am partly clipping a hopper minecart to the bottom rail while half of it is still in the cauldron filled with lava destroying it and thus dropping both the content of the minecart as well as the minecart itself. The content of the hopper minecart always drops on the hopper with the rail on top, the hopper minecart itself however gets picked up by one of the 2 hoppers depending on which one is placed first.

Steps to Reproduce:
Build a contraption as shown above and take note of what hopper was placed first then place a hopper minecart on the track. (Redstone lamp and comparator are not of importance)

Observed Results:

Minecart gets dropped and picked up by the hopper that was placed first. It should be of note that upon reloading the world or the chuncks this always works as if the hopper with a rail on top was placed first. 
Sidenotes: This works in every direction.

Expected Results:

Either upon reloading the world the behavior doesn't change to the second hopper taking the minecart or the behavior shouldn't be dependent on what hopper is placed first.

Video:
MC-256052.mp4