We'll have to agree to disagree

A few years back I was booking a reward trip for a friend, and told him sorry, only coach available on this flight. He emailed back, saying he can see it.

So I logged out, logged back in (must have been a stale, old login), and lo and behold, flight had availability in both C and F

I realize it's almost like spotting a unicorn, but I can vouch that that one time (and one other time IIRC) it did work. IIRC, was Plat at the time.