There is the truth that here is someone who truncated the users table and because of that it caused the company great harm.
Here's another 'truth'.
1. The company lacked backups
2. The junior developer was on a production database.
Note: I'm from the oldschool of sysops who feel that you don't give every employee the keys to your kingdom. Not every employee needs to access every server, nor do they need the passwords for such.
3. Was there a process change? I doubt it, likely they made the employee feel like a failure every day and remind him of how he can be fired at any moment. So he did the only thing he could do to escape: Quit!
Horrible and wrong, if there was a good ethics lawyer around he would say it smells ripe of a lawsuit.
... That said, that lawyer and lawsuit won't fix anything.
If it hadn't been a junior developer who nobody noticed or cared was using the prod DB for dev work, it would have been an outright failure. DBs fail, and if you don't have backups you are not doing your damn job.
The CEO should be ashamed of himself, but the lead engineers and the people at the company who were nasty to this guy should all be even more ashamed of themselves.
Giving keys to irresponsible people seems irresponsible ;)