If you shoot an arrow from crossbow it will be shot same place like you are standing even if you are falling, unlike bows.

To Reproduce:

1.  Make a pillar and mark 25th block with another colour (lime).
2.  Place a block horizontally 20 block away from top.
3.  Get top on that block and look straight to pillar.
4.  Charge the bow, fall and shoot as you saw marked spot (lime), mark the block (red) that arrow hit.
5.  Charge the crossbow, fall and shoot as you saw marked spot (lime), mark the block (orange) that arrow hit.

Bow's arrow will land between 20-10 block.

Crossbow's arrow will land between 25-20 block.