Originally Posted by Globaliser

There's no need to be disappointed at all if it is, provided that you're expecting it to happen and you have separated (or can quickly extract) what you need for the flight.

Bags that are taken off you at the aircraft door are put in the hold, but they are returned to you at the aircraft when you disembark and do not go onto the baggage carousel. Given that the process is specific to that aircraft and the bags don't get moved more than a few yards, there is virtually no room for anything to go wrong. So frankly, I think that this is even better than carrying the bag onboard with you - no personal gymnastics required.