Grenade bouncing off leaves

I'm not sure of this is a technical issue, bug, feedback or really good collision. I was playing a game of king of the hill and threw a grenade. I was aiming at the leaves on the tree in front, expecting the grenade to go through the leaves. The grenade bounced back towards me. This could be my misunderstanding. That grenades going through leaves in other games I've played could be bad design. I did this on another tree same thing happened. It just felt immediately unusual for it to happen when it occurred. The issue happened on the map liberation peak.  I threw a grenade at tree leaves on the Empire state map and it when through the leaves.