As a UX person, I'm intrigued by this idea, but I would probably avoid creating situations where it is necessary to apologize. If you confirmed a flight, hotel

As a UX person, I'm intrigued by this idea, but I would probably avoid creating situations where it is necessary to apologize. If you confirmed a flight, hotel and rental car, but then came back with a "Sorry!" later, that would be a negative experience for a user. They may have passed the confirmation on to others or set other plans in motion, which may also have to be "rolled back". You would need to compensate customers for the inconvenience. The way to avoid that is to show requests in a pending state, but this has other implications. Users will want to continue to shop and to cancel pending requests, which might mean lost sales. Generally it's more important to paper over the realities of a complicated system when you have a customer-facing self-service tool. Exposing those realities might create too much complexity for self-service, and you may need sales and service people to manage it. Basically you've built a travel agency instead of Expedia, which, again, is more costly.