Cassius Grady (Joe Davidson)

[Aussieguy]

He hit Hamish. Hamish collapsed a bit later on due to it and fell in the pool and drowned.

The story has pretty much ended. I could be wrong but I highly doubt there is going to be a big reveal that he was murdered by someone else. It's done.

Yep they didn't go into details but would assume the hit on the noggin led to bleeding in the brain and eventual death.