Gromp vs Minions

I was playing the new rift beta on the live server and noticed a strange interaction with Gromp and the lane minions. If you use a ranges attack of any kind to gather aggro from Gromp and there are no valid targets near him in the jungle, but the lane minions are passing by, Gromp will turn around in his spot and start killing the lane minions as they travel by. This was about mid to late game when I saw this and he was 2 shotting most of the minions. Also Ashe started to fight him at her max range when this was happening and he didn't care because the lane minions were closer. I feel people migt be able to take advantage of this to deny their lane opponent cs/exp. Not sure if this was intended. I wouldn't think that a jungle monster would have vision of what is going on in lane. Also as a side note, the minions just kept walking by. They acted as though Gromp was not there.