Well you could have fun with QF lounge agents who are clueless to the rules at all...

Had one in AKL insist that the guest has to be on the same flight as me. I pushed back hard, there was no supervisor working (Jan 1) and these were clearly contract employees, not actual QF workers.

She let us in reluctantly on a 'one time basis' after I read her the OW rules verbatim from the website, she said she'd "been told that the guest must be on the same flight", this was after fiddling with her PC for a good minute or so and seeing the boarding pass that was clearly a different airline. (I was on AA, guest on CX which was delayed)

My guest did not leave with me (yes I know that's the rule) and didn't get kicked out either. She stayed to enjoy plenty of fine NZ wine and left on her own accord when it was time, so was happy with the outcome.