Good on you for noticing this. However, it's not really wrong per se because common usage accepts in many cases the masculine form when referring to titles and positions. A manager is masculine, a manageress is feminine. You often see an actress referred to as an actor, a waitress as a waitor. etc, etc. However, it's never acceptable to do it the other way (i.e. give a man a feminine title - except Queen but I think that's something else). Like in Italian you refer to a group of boys and girls as a group of boys, unless you make the extra effort to differentiate which hardly ever happens.
