You always give whatever is the greatest advantage to the non offending team. In this case the penalty was given for the second offence. The reason play was not stopped at the time was because advantage has to be allowed to see if an advantage is gained by the non offending team. You can also hear Thierry asking the VR for clarification, which according to the protocols we all work by and agreed by the SL coaches he is entirely at that point entitled to do.
As for SteveiM13's comment about the sin bin for Crusaders robbing them of a player, the rules are plain and simple that any delay of the 20m restart is an automatic sin bin.
Bentham did not send Manu off as it was not a sending off offence as has been shown by the video review panel. He did not sin bin Peter Fox because contrary to popular belief slowing down the ptb is not an automatic sin bin and there is no such thing as a "professional foul", it's another myth put about by tv commentators. The penalty was the correct decision. There are only 2 occasions when an automatic sin bin is allowed and that is a deliberate delay to a 20m restart as in the case of the Crusaders and a late challenge on the kicker.
Sorry, but can't remember the particular Tomkins incident you are talking about so can't possibly comment.