What he means is that since Infected receive no damage no matter how far they fall, it could be possible to use the zombie's code for getting no damage from falling and replace fall damage with it.
[Summary] you can use the zombie's code for no fall damage for the code for normal people, and thus receive no damage whatsoever from falling as a human.
-Edit-
yeah... have to think about it a little bit >_<
anyway, hopefully you understand that