My "proof" was never independent, and I didn't notice until today

Been building toward a three-proof model for confirmed execution: plan integrity, execution-time validity, post-dispatch evidence. Today someone asked a question that broke the third one cleanly.

The question: if the only evidence that something executed comes from the same system you're trying to verify, is that actually evidence, or just the system's own claim about itself?

My planned post-dispatch check was going to be an SMS provider's delivery webhook, a calendar API's confirmation response. Then it hit me: that's not independent evidence. That's the system I'm verifying, reporting on itself. I don't have a second phone confirming a text arrived, or a separate account reading the calendar from outside. For a solo build, true independent verification of a third-party API might not be achievable at all — only degrees of how much I trust a given provider's own word.

Which means DENIED_UNRESOLVED might not be a temporary state I eventually close for a lot of actions. It might be honestly permanent — not because the verification isn't built yet, but because independent evidence genuinely isn't available at this resource level.

The provider's webhook is still evidence. It's just weaker evidence than true independence, and I think the actual discipline is labeling that difference explicitly instead of letting a provider's self-report quietly earn the same trust an independent check would.

Three weeks into this model and I keep finding the next layer down instead of the bottom.