#1 Keep good finger control so that he can't lock his hands.
#2 Keep your head away from your knee.
Good hand control, movement, and keeping your head away from your knees should help.
When we face a cradle team or individual we tell our guys to keep their head up and to be sure to get the first move off the bottom.
It's important to remember to keep your head away from your knee in all positions as I've seen more than on guy hit with a standing cradle when they get lazy and let their head come down close to their knee.