Why does your article on sexing adult chickens state unequivocally that hens do not Crow?
Hens have the ability to crow but the normal levels of estrogen suppress the desire. If a female is crowing her estrogen levels are low and the testosterone is affecting her. In such cases the hen starts to take on male secondary characteristics and will outwardly look like a rooster with the larger comb and male type plumage. This is referred to as sex reversal.
The chicken with the muffs and beard is developing male plumage.