I am starting to think he really did. And that Tony knows.
Basically, Connor wanted Leo out, was jealous of Leo, and in a psychotic moment, smashed Leo's head in from behind with a golf club. From there, pulled him into the bathroom, and pulled him up against the door, and then closed it with Leo's body pressing against the door making look like Leo somehow killed himself.
And then Connor quickly moved into Leo's bedroom and Tony's house once Leo's corpse was found and removed.
Connor has dropped lots of hints that it was him. Police forensics useless. Did they even bother to look for blood on the golf club? Did they even bother to take Connor's fingerprints and see where in the bathroom or elsewhere they might be? Did Tony make a little payment to local just to let it all pass...maybe as a misguided gesture of friendship to Connor?
When this all comes to light, Tony will either say that he simply could not have imagined Connor did it, or that one tragic death does not justify another friend going to jail. But deep down I think he knows.
What a very strange group of nutcases these guys all are. And Tony, a grown man, surrounding himself with all these influencers, ladyboys, nutcases, people with "magical powers", "bio-hackers" and looksmaxers etc - all very surreal and also quite gay...