Also, he is not a hacker, just an asshole. Having the admin login and password doesn't make you elite. The only weakness he exploited was himself.
What they did; and more importantly have they recovered and not commited another crime of similar circumstances.
P.S. I knew a kid when I was younger who helped an ISP start up in Colorado Springs in the late 90's... he got fired and he hacked them and spent 6months in jail; eventually they re-hired him after he got out of jail only for a repeat offense.
There is a point; he did it twice. The first time they could pass it off as they didn't know; the second time they hired him they were legally liable.
So this gentleman should spend some time in jail for what he did.
Yeah, that. Also, secure backups and compartmentalized systems and data access.
Automated tools may need to delete and list; but heck off site secure backups are an amazing thing.
Regardless of what crime they may (or may not) have made; you are looking for the person and what they do. Not what they did.
This is a common problem; we look at the past a bias of the future. Life only works out that way if the person is too unwilling to change; and that again is something you should look for in the hiring process.
Lastly; hiring ex-hackers isn't a bad thing. Caring about a background check when hiring an ethical hacker or someone who turned their life around; only shames them and pushes them back where they came.
So be careful or you only end up criminalizing being a criminal.