So, taking this story at face value, I'd say the obvious: not his fault.

If your system is built in such a way that the production database can be nuked from the most junior developers command line, then that junior developer is definitely not at fault.

But this story just doesn't pass the smell test. I've worked in some sloppy, slipshod places and even in the worst of the worst dev shops there's no way this could have occurred.

Either this person found the most absolute, bush-league shop there is, or he or she or xhe is completely full of crap.

For me there's too many eye brow raising parts to this story so i'm sceptical of its validity. Still, it prompts those 'did you hear about the x that done y and z hit the fan' stories.