"From a common sense perspective it is a game we play 80 minutes under the normal laws of rugby and we said we've done this three or four times - it is not like a one-off or hastily organised," Foster added. "The reason we play two teams is it actually makes the game harder for us. This is not a training run.
"We've got New Zealand's No 1 ranked referee in Glen Jackson; we've got judiciary. We treat is as a real game. If someone gets sent off in this game they have to go through the same process Sonny had to go through.
Listen to Ian Foster talk to Nigel Yalden
"Under all purposes this is a match and we just wanted the chance to express that. Fortunately, we felt common sense prevailed."
Foster said the All Blacks match against Counties and Taranaki will not feature rolling substitutions.
"You have laws that first-class games are played under, and more flexible rules that preseason games are played under. World Rugby knows that. Whether people like that or not that's always been how World Rugby has treated those games for suspensions.
"In our case we generally strip about 26 so we have very limited substitutions so it would fit under any preseason match in the northern or southern hemisphere."
In a statement, World Rugby said it will seek clarity on this issue from its regulations committee in September.
"If the byproduct of this is they get a universal definition of how they want to do it that's great," Foster said. "Quite frankly, it's a difficult one. You've got World Rugby trying to come up with rules that suit both hemispheres and they're very different in the way they're structured.
Foster explained northern hemisphere suspensions were served at international or franchise level while in June and July the southern hemisphere also had potential provincial and club duties to factor in.
"We need some better understanding from the northern hemisphere that there are different levels players have to play in.
"World Rugby quite correctly keeps a close eye on games the player never intended to play in. We understand and agree with that. That's why when we initially looked at the programme Sonny would have played in a Counties A v B game.
"We feel the right decision has come and it is very meaningful for Sonny."