Why do you think this reflects badly on him? He deleted some repositories that he made in his spare time? It wouldn't affect my decision to hire him negatively, and the experience that he demonstrated with the project is still a massive positive.
Without knowing him, I'd worry he'd do that in other organizations he's a member of. What if he has a fight at work? Will he delete stuff or leave in a hurry without making arrangements for other maintainers?
I'm not saying he would do these things or that he's a bad person, it's just something I'd be cautious of given his response to this. If I were his manager or coworker I certainly wouldn't fire him, but I would talk to him about it.
As for next steps, I think the maintainer should undo the deletion, apologize for the rash response, thank the sane members of the community for their appreciation, and leave a message that he's disengaging for awhile (it could be forever). That would be the perfect way to go about it. It doesn't leave a bad taste, and it's an overall good look. It's the high road.
I still feel incredibly bad about how the community treated him. He was doing amazing work for all of us, and some careless folks berated him needlessly. There are better, more constructive forms of criticism.