A dog that goes to the area of a fall, hunts,fails to find, and then leaves the area to hunt for another fall, or that drops a bird it is retrieving and goes for another,
The key word is HUNTS..
So if a dogs does this, and there isn't any mitigating circumstances,, per rule,, the return to an OLD FALL,, is judged as a Switch, and graded a zero. in perseverance.. In SENIOR, as well as MASTER tests..
It would seem to me, regarding this issue, that experienced handlers ,would be well aware of what the rule book states..