He would never know
Author's Note: Someone asked me to show Oliver blaming himself and Thea's reaction to Roy being dead so here's Oliver blaming himself (I have no idea how Thea would find out since she went with Malcolm and even if he somehow found out he probably wouldn't tell her)
Disclaimer: I don't own Arrow.
When Oliver, Felicity and Diggle got back to Starling City Oliver went to the mansion and sat down in the living room while holding a red mask.
Now that Slade was put away Oliver allowed himself a moment to feel guilty about Roy's death. When he had found Roy's body he had been shocked and sad but Slade had had to be dealt with so he had grabbed Roy's mask and pushed his sadness and guilt aside but now alone in the mansion it was coming back. Even before the Mirakuru Roy had been a good fighter and Oliver had trained him but apparently that hadn't been enough. As Oliver held Roy's mask and thought these things he allowed a tear to fall from his eye. Suddenly his cell phone rang. He looked at the caller id. It was Laurel.
Author's Note: So there you have it (if you're wondering why Laurel is calling Oliver it's to tell him what happened to her father).