quick question about grenade launcher

Let's say I'm at the bottom of a wave, and an enemy is at the top of the wave. I shoot a grenade at them, but instead the projectile hits them before it even gets close to the waves and hits them in their lower side. I'm curious, as long as the projectile hits the enemy directly, is that a max damage hit or reduced damage since it didn't hit them from the top or what?

 

Direct hit is usually good for max damage, but I have (especially hitting defenders) seen extremely reduced (up to 50%) damage.
Probably lag