Aftermath of Crap Contractor - Can I hang from this?

[Elaine E.]

We hired a contractor that patched our recessed light box in order to have a flush ceiling a few weeks ago. I know this patch job looks like crap, and we seriously regret doing this project in the first place.

But moving forward, we went to hang a 4lb fixture today, but discovered there's no stud or support under where they patched it and where they pulled the wires through. Is this a code violation? 

It possible to hang this into just drywall? Or do I need to tear it back open and install proper supports?