Dennis Lillee said in 2007 that he was one of the fielders that day at mid on I think he said who were meant to begin walking in as the bowler made his run up and for the ball in question he failed to do so so was outside the circle when the ball was delivered This would mean given the fielding restrictions in effect the ball was a no ball I have done a brief search for a source for this but I recall seeing it in an interview in 2007 so I presume there is a written or video source out there somewhere