Whats the best example of it takes 20 years to build a reputation and 5 minutes to ruin it

that you know of?

Example:

Dude I worked with had 30 years in our trade. Other people from other companies would call him for advice. He was a master of his craft. And he was Ned Flanders nice.

He was fired for downloading child porn on his work computer. A lot of it. Over period of a few months.

Even after he was fired most people assumed he had been caught using company materials to help do service work at his church or maybe, at worst, smoking weed.

He still had a decade before he could retire and I don’t think he has worked in that decade.