I’ve just watched it at quarter speed. Defender’s body direction was back and across the goal line, feet behind the line when he headed it. Angle not helpful in determining the exact position of his head, but I am confident at least part of the ball was across the line; whether it was all across the line was linesman’s call, and he took a quick look along the line as if to confirm the ball’s position relative to the goal line, before heading determinedly back to the centre.
