The Lions Ruck Play

We have traditionally favored a game with strong ball carriers, but over the years our ruck has become a mess. The likes of Fat Alberts limbered from ruck to ruck, often exhausted in the first half alone. Our ball carriers are often isolated, making the breakdown a buffet for the opposition. This negated our strong ball carriers to aimless donkeys.
The Lion's pods at the back of rucks are a good way to give the scrumhalf clean ball- even if it is not always quick. 
In the game at a critical time, the ball was about to exit the ruck, and then the Lions player(Kriel, I believe) kept the ball under his foot, by being more parallel to the ground to cover the ball. The New Zealand player was going to make the turnover but did not expect Kriel to trap the ball with his foot like at the base of a ruck.