Card on the table, I'm biased as I'm a DBA ( most hated of the hated admins! ), click those downvotes now!
The real problem as I see it is why was a developer allowed free reign on a production system? They should be restricted to dev systems on a day to day. Devs ask for temporary access to UAT and prod systems when required to fix things. Their actions are audited and recorded so all parties are in the clear if anything goes wrong, everyone's arse is covered.
Sorry first day on the job then you are ultra careful and check everything first, at least that's what's in my mind in those first few hours. I don't mean to be callous but there is a reason they don't pay IT people minimum wage. We get paid damn good money for our knowledge, attention to detail and professionalism, we get paid danger money 'cos we carry the can for the company systems. I've had to fix things when stuff has gone wrong, shit happens as a fact of life but you try to mitigate that with a bit of care and attention. Too many people treat systems, especially databases, like dirty black boxes that can do anything. Sadly the shit often flows downhill to the hated DBAs like me, who then have to pick up someone else's crap. It's what we do but we'd appreciate it if you just stepped back for a second and thought before you click GO to submit that untested transaction, to make sure it's pointing at the right system.