I saw the AI start a rolling maul in open play but I can't seem to do it as the player!

I kicked the ball into space, the AI player picked the ball up, turned round crouched down and his other forwards joined onto him to form a rolling maul. It was great!

What I noticed is the player bumping into one of his team mates and this seemed to trigger a rolling maul. I tried it but keep on getting tackled before I can bump into one of my players!

Has anyone else seen a rolling maul in open play? Any ideas how this can be done?

Cheers

J