When a great scrummaging side pulverizes their rivals, there is no mercy rule.
It's up to the pack on roller skates to deal with the drama by improving or using their subs bench otherwise any competent referee is going to penalize them and probably send someone to the sinbin.
Then the problem will get worse. That's the skill and reward for a side with outstanding scrum technique.
So why does World Rugby have a rule which says if two specialist props are injured during a match, scrums will revert to golden oldie rules as we saw when the Springboks hosted the All Blacks at Ellis Park.
Springbok captain Schalk Burger missed a trick when his side had the All Blacks on the rack.
He should have argued with referee Jerome Garces that his reserve prop Trevor Nyakane was up to the job because even if his technique was a little rusty, eight Boks should have had the nudge on the All Blacks.
Naturally the All Blacks rolled over like a seal on a hot rock when told about the no pushing scrums. RugbyLotto was theirs. Richie McCaw was not going to argue.
World Rugby doesn't have regulations that stipulate a tackle free zone around a quasi-halfback if two are injured during a game or that there should be no contesting up and unders if a side is forced to use a utility fullback.
It's mighty unfortunate if multiple injuries occur in the same position but it should be part of the intrigue at test level.
The All Blacks did not get any leeway at the 2007 World Cup when Daniel Carter then reserve five eighths Nick Evans were hurt in the quarterfinal against France.
At Ellis Park the All Blacks were a man down with Sam Whitelock in the bin and the Boks were smelling blood.
It's hard to believe such a gladiator as Springbok captain Schalk Burger did not protest more strongly, especially with the test at such a crucial juncture.