Yes your correct the Baggage should have been unloaded and New load sheets and Manifests, provided to the Operating Crew. By how much did you miss your flight by, hours or minutes or seconds.
But if you prechecked ahead you baggge as some poeple do to alleviate excess baggage fees, there is special scope in the rules for this.
For example when I travel back to oz from London I will be sending some of my bags ahead of me by QANTAS Cargo. This will save around 500quid in excess baggage. I hope .
Sheep