Ahh, yes, I see it -- apologies.
Looks like this example too is flawed, the Black King is simply too close to the action and Black's pawn is on the wrong file. It is a draw with the Black King on b3 instead of b4 or with the black pawn on any file except a, h or as it turns out, d. I think the illustration of the point was made regardless.
Tricky position this.
Typo. I meant Qa7 is mate.