How to be a supportive friend/possible love interest

I(19) received a lot of hate on a post a few days ago on a post questioning a guy(18) I'm talking to sexuality and after some thought I understand I was wrong. The post was about him telling me he's going out with friends to try candy flipping and his friends agreed to stay sober to babysit him while he tried candy flipping. They posted a video on Facebook on him naked and throwing up. He got too drunk and was having a very bad trip and his friends were laughing and saying how he and one of the guys had sex. Then kicked him outside and made him sleep outside and have a bad trip. He doesn't remember anything and was humiliated. He doesn't even remember having sex with the guy and I understand now that there was no way he was in the right mind to consent to sex. He stopped talking to me because he was ashamed but we met up today and I can tell he's not doing very well mentally. I realize now that I was wrong and the situation was R-word. I'm not a bad person I promise. I'm just stupid but I do want to offer support and be there for him. I still do want to date him but at the very least be a friend.

Edit: Candy flipping is mixing LSD with Ecstasy. I've done them both separately but never mixed them before. There's really nothing fishy to the story because I saw the video myself.