Dog (big one, 90+) sent for the flyer. Picks it up clean, returning like a locomotive back to the line for next bird. Handler blows a sit whistle when dog is about 5 - 10 yards away, then quietly heels him in. When asked why that was done, he explains that he does that to preserve his bad knee. The dog had been known to wipe him out as he flies back to heel. One judge suggests he not whistle the dog to a stop like that again.
Would you penalize for this? If so, what rule applies?