Originally Posted by
Efrem
Another concern, if you want to get off in - say - London on your return, is that your airline didn't agree to take you to London. They agreed to take you to Oslo. If anything goes wrong with the airplane that was to take you to London, they're within their rights to put you on a non-stop to Oslo or on any other flights that get you there.
A very valid point, which people often forget. Whilst there is little chance of being put on a direct USA-OSL routing (because few of these exist), you might get put on a USA-CDG-OSL flight, which would be a real pain.