Warlock's throw their grenades underhand, but when using a stasis grenade of any sort, the warlock throws it overhand. This doesn't bother me at all that the grenades throw this way, but I just thought it was kinda interesting that they did. I guess Bungie just coded the same animation of throwing grenades to all of the 3 classes and forgot that warlocks throw their grenades underhand. Maybe they could change the animation in a later date to make it more faithful to the warlocks, but knowing Bungie, they probably won't (I know that the Warlock grenade animation isn't exactly underhand, but idk how to describe it so I'm saying underhand)