Happened a time or two to me ,only a bird or three out and I`ve not had any evidence (or will) to question it tbh although it does annoy!!!
As others have alluded,refs do difficult job and we are all only human.
Poor buttoning has lost me a lot more birds......
Already done but thankyou for bringing it to the attention of the forum ! Everyone who shoots should be responding to this .What is CPSA doing on the subject?