We sat at the gate whilst her checked bags were found and taken off the plane. Whilst it was extremely frustrating, it only took about 20 minutes.
On the way out, a transfer passenger's bags made it to my LHR-LAX flight, but the passenger did not. It took an hour for those suitcases to be found and removed.
Couldn't agree more that airlines should take steps to stop repeat offenders flying - that's got to make economic sense, both in terms of not having aircraft sitting on aprons for hours and also by keeping to schedule and pleasing those passengers who do turn up on time and want to fly.