"He lost balance, you could see he tilted and what happened. I feel for the refs in situations like this because technically they saw things and they make their decisions so I get all that. Now we've got a chance to sit down and analyse it we'll have a good couple of conversations."
The All Blacks adapted and adjusted to their 20 minutes while one man short to outscore the Wallabies 5-0 during that time.
World Rugby refused to include the ability to replace red carded players in their global rule trials but with full Southern Hemisphere support, Sanzaar pushed ahead with the law for the Rugby Championship. That allowed the All Blacks to bring Damian McKenzie off the bench to fill Barrett's void 10 minutes into the second half.
"That's why all the Sanzaar countries were all united in wanting to carry on this global trial," Foster said. "We were the one on the end of it so we benefitted by only having a 20-minute red card but we were a keen supporter of it even before the game and today's incident justifies it."
The fallout from the decision to delay the All Blacks' departure to Perth by a week – until the Rugby Championship host destination was confirmed – brought strong criticism from Australia which included the team's commitment being questioned.
Foster made a point of addressing that issue, suggesting it played a part in the dominant nature of the performance.
"I didn't really like questions about our attitude not being committed a few weeks ago – we were 100 per cent committed – and the team showed that. An All Blacks team always wants to turn up and play and it really did come down to our attitude on defence. We put them under a lot of pressure through our defence and we forced them into some errors and loose offloads.
"We were really committed, the desire to play and look for opportunities and attack both with and without the ball was clear and obvious and we stuck at it. It wasn't a picture-perfect game in many ways but the attitude to run and scramble was outstanding."
Having suffered a record defeat in Perth two years ago, when Scott Barrett was red carded, the All Blacks were keen to avenge that result. So, too, did Foster challenge the team to register their first clean sweep over the Wallabies since 2018.
Beginning the tour, which will see the All Blacks play five tests in five weeks, with another bonus point win leaves them well placed in the quest for the Rugby Championship title.
"It was pretty important. We've spoken about a tour like no other in many ways so to start off with this one is special. We were pretty open and honest about wanting to do 3-0. We haven't done it much before and it meant a lot to us.
"There were whole lot of factors – a Perth performance a couple of years ago – but the main driver was to do something we hadn't done for a while. To go three zip and to play in those circumstances I was delighted."
Had the All Blacks kicked their goals they would almost have notched another 50 points on the Wallabies. Despite Beauden Barrett and Damian McKenzie missing five conversions between them, Foster applauded Barrett's calm leadership after Ardie Savea and Codie Taylor left the field with head knocks in the first half.
"There was very little breeze but the bright thing in the sky might have got in the eyes of the goal kickers for both teams.
"In Beaudy's case if he had to get one of the two things right in terms of goal kicking or playing really well I'm really pleased he got the right one. He played really well with his decision-making early, and he was really calm when we were under a bit of pressure with the card. He showed his class. The goal kicking will come right."