Mopzart
With respect - it is not one missed tackle that cost the Springboks the RC - it was a series of mishaps in both tests that caused it.
Eden Park
Lets start with the test in Eden Park. We all agree that the ref buggered up the game and that it was made virtually an impossibility for the Springboks to win that game - at best they could hope for a loss without giving away a bonus point. Why was that bonus point given away? There were two tries scored a result of the poor play of one player - Morne Steyn. Lets deal with those two tries in particular:-
* The first try stemmed from an attack by the All Blacks ending up in the Springboks 22 - where an AB player hung onto the ball and a penalty was awarded to the Springboks. Morne kicked - but did not find touch. The All Blacks counter-attacked and the counter-attack ended up in a try for the All Blacks.
* The second try had much the same impact. The Springboks is on the halfway line and a penalty is awarded to them. Morne kicked for touch - missed it badly and the ball went over the dead ball line. Result a scrum from where the kick was made. The All Blacks got the ball from the scrum and an attack followed - ending up in a try.
The question is - were those two tries inevitable and the answer is NO. It was caused by poor play and in the specific two cases by Morne Steyn. He is an experienced flyhalf - yet in those two cases he made schoolboy errors. End result - the All Blacks got a bonus point from the match that could have been avoided by proper play.
Ellis Park
In the Ellis Park test the All Blacks scored 5 tries. Lets analyse those 5 tries:-
* The first try resulted from a missed tackle by Alberts on Read - followed by a miss tackle by Morne Steyn on Ben Smith after the latter got the ball from Read. Both were serious tackle deficiencies and they are indeed to blame for the try.
* The second try - scored by Messam was another mishap. Aaron Smith got the ball and tried to get through the defence. He is tackled and Alberts is a meter away when it happened. Being the nearest player to the tackled player he is supposed to go for the ball recovery - but he failed to do so because of clumsiness - he fell over his own feet. The long and short of the story is - Alberts should have recovered the ball from that breakdown as the nearest player to the point of breakdown - he did not and the end result was a try by Messam.
* The third try was a mess. The siren for halftime is about to go off. The AB's are in the Springboks 22 - when there is a turnover in possession. Instead of doing the obvious - namely kick the ball out of touch - Morne Steyn passed the ball to De Villiers - who passed the ball to Engelbrecht - he got tackled and there is a turnover in possession and Messam scored his second try. That sequence should - according to Naas Botha - never have happened and it would not have happened if Morne Steyn did what a normal flyhalf would have done - kicked the ball out of touch.
* The fourth try was the result of two missed tackles - after De Villiers went out of the defence line - the first one a feeble attempt by Morne Steyn - the second one an equally feeble attempt by JJ Engelbrecht.
* The fifth try also followed upon a missed tackle by Morne Steyn - or rather to put it in perspective - Read passed within 2 meters from him and he made no attempt whatsoever to try and tackle him.
Summary
It is rather simplistic to blame one player for the loss of the RC. If there is to be blame assigned then the players involved are -
* Morne Steyn - his name is mentioned adversely in the case of six of the nine tries scored by the All Blacks in both tests;
* Willem Alberts - his poor play resulted in two of the tries score in the Ellis Park test; and
* JJ Engelbrecht - he messed up in the case of the try scored by Barrett.
In the whole process Engelbrecht is a rather small cog in the wheel of misfortune - Morne Steyn a major cog and the second biggest cog is Willem Alberts. I am sorry to differ from you - but the above is a true reflection of what really happened in the two tests lost by the Springboks.