Unfortunately we do not account for payment split failures in our zap receipts - we generate a single zap receipt for all splits.
This is a tradeoff because the zap receipt cannot be updated as it's not a replaceable event. The fact that we have multiple splits makes it complicated and even if we did wait for the result of each split - that would not render easily on other nostr clients.
My view is that a more flexible payment receipt event kind would make things much easier - I proposed this in 2024 but it had no takeup -
https://github.com/nostr-protocol/nips/pull/1339We also chose to do things this way to put the burden on receiving wallets to reduce their payment failures.
I know this is not ideal - but I cannot think of a better way of doing it right now given the constraints.
Happy to hear suggestions.