I've also seen NRRs denied when processed under a regular TM's numbers, but then allowed for same-dept exchange if you sign off and have someone with supervisor numbers log in to process the return. Doesn't work for everything, but it's sometimes worth a shot.
I like having the Emergency Override Code for those issues that need special consideration, but now I'm getting a couple of 'select' team members calling me over for almost EVERY denied no-receipt (I call them my 'over-vibers'). The worst part is, when I get to the service desk, they ask me "Can you use your override code for this?" right in front of the guest.
Maybe this only bothers me, but I think that's basically telling the guests "I have the ability to override this, but I'm not going to." True, but I don't want every guest I deal with knowing that. It was a whole lot easier when I could [honestly] say "No one in the store has the ability to override this," call 718 if they threw a fit, and then let them tell the guest "no" for me.
That said, I've been training those over-vibe TMs to say "Can we attempt anything else for this guest?" instead.