Need the edit feature for cycling also. I constanly for get to turn off the Garmin after a ride so I record these invalid laps driving home. Wish I could ride that fast, but it would be nice to delete them. Not to rub salt in the wounds but Strava can do this with their crop feature. Not perfect but better than nothing.
I would also suggest a sanity check in the watch - If I am swimming 50 laps between 28-33 seconds, I will not suddenly swim two laps at 14-15 seconds each (or even one lap of 5 seconds followed by one of 25). That can't be too difficult to implement in a firmware update, can it? Simply decrease the probability of a turn if the current lap is significantly quicker than the previous one - I think this would eliminate 80% of my "double counts", which would make the majority of my workouts completely correct.