Hugo's There
Wise Old Thumper
If that is the case, I guess the trouble is that bunnies are very good at hiding illnesses and something might be sub-clinical and would be triggered by such an event. And you wouldn't know whether you had a bun in that category until you'd let them out and then they'd become ill.
Exactly this. As I said above rabbits are good at hiding underlying problems so why do something that potentialy put them at risk when there really is no need.