This guy Joshua Z.H. Wu does not come out looking good in this blog post. He doesn't realize it, but he just lost a lot more than $10k in lifetime earnings too. Someone willing to nuke something that their friends/coworkers built in this fashion is just not someone you ever want to hire. You find this kind of crap on Google, and you just don't call him back or offer an interview.
After all employers are human too, and when you delete the production db, make everyone pick up your mess, quit, and then have the stones to ask for your long-forgotten referral bonus for current employees in a chipper tone when you are already at another company...yeah, he's kind of a douche.
I'm sure he can be legalistic about it, and I'm sure there are no end of lawyers out there willing to huff and puff about the evil employer but...douche.