Damn. Ima idjut. So you have just schooled me, thank you. If an invoice appears, and someone pays it first, then it is done (kinda like the #Bitcoin double-spending thingy).
Discussion
Exactlyy
nostr:npub1hcwcj72tlyk7thtyc8nq763vwrq5p2avnyeyrrlwxrzuvdl7j3usj4h9rq should make that error message more friendly.
Something like:
Oops! Looks like that invoice is no longer valid. It may have been paid or has expired.