Law 32, 3e states: (it's a fair catch if) a fielder catches the ball after it has crossed the boundary in the air, provided that after being struck by the bat, the first contact with the ball is by a fielder, not touching or grounded beyond the boundary, who has some part of his person grounded within the boundary or whose final contact with the ground before touching the ball was entirely within the boundary. - See more at: http://www.bigbash.com.au/news-and-...s-controversial-decision#sthash.zHoRlqFr.dpuf
So right call made in the end.
Wasn't his final contact with the ground before touching the ball again over the boundary?