I feel like whatever authorities are involved should have done more to prevent him from retiring. I get the other adventurers being eager to tear down this genius that makes them all look bad, and throwing spiteful comments his way. But for the guild, and for the people who contract the guild, this guy is out there actually solving their problems. I mean, someone reported those wyverns, meaning someone was troubled by them. It sucks that there was a dragon nearby, and the guy getting PTSD from watching helplessly as the town was destroyed is reasonable too. Specially if he's been such a talented guy so far that he never faced any setbacks before, like losing a party member in a mission.
It doesn't look like he was held accountable for the damage by the guild or the local authorities, since he is not in prison or made to pay a massive fine. But the guild should have offered more than one secretary saying "it wasn't your fault" to keep the guy working. Not sure how adoption works in that world, since he apparently gets to keep the babies he found rather than, I don't know, hand them over the the local lord or church. But the guild should offer him a relaxed schedule, or hire a babysitter if he wants, or whatever, just to keep this prodigy working for them. The local authorities too, they should be offering him a position as knight or something, since raising children means staying put in one place.
This whole "ok, we'll let you drop off the face of the world and make no effort to retain a once-in-a-hundred-years prodigy like you" is a bit forced.