What Haslam was talking about is that for maximum braking, c_g_ height must be reduced to as small a value as possible. That happens at the front, naturally, as brake dive. At the rear, the brake caliper is intentionally attached to the swingarm so that brake torque also compresses the rear suspension somewhat, further reducing c_g_ height. What Haslam means is that if the rear brake ceases to compress the rear suspension, the back of the bike will rise, raising c_g_ height slightly, and forcing the rider to reduce front braking to keep the rear of the bike from rising farther. Each rise of the rear raises the c_g_ height in a vicious circle that can ruin one’s whole corner approach.