Can you report people for intentionally not ending the game?

Last game, our team got ace'd and our nexus was wide open to end the game, but instead of ending, the enemy Darius went back to base while he was literally standing right next to our nexus. The Rek'sai tried to end the game, but the nexus was left with like 500 hp because she didn't have enough damage. Darius just wanted the game to go longer so he could get more kills.

Is this reportable?