Ange Postecoglou launched an extraordinary rant against technology in football despite Tottenham Hotspur claiming a 1-0 Carabao Cup semi-final victory over Liverpool, and questioned why English fans would not stand up against relentless change.

Postecoglou, whose side took a first-leg lead through a controversial goal by teenage midfielder Lucas Bergvall, was on the touchline as referee Stuart Attwell produced the English game’s first in-stadium referee announcement, as part of a trial process.

After Bergvall was controversially not dismissed for a possible second bookable offence moments before scoring the winning goal, Postecoglou delivered a remarkable answer in which he expressed his surprise that English people – as “custodians of the game” – have allowed so many changes to the sport in recent years because of technology.

“I’m really surprised at how people in this country are so easily letting the game change so much so quickly,” said Postecoglou. “It’s changed more since VAR has come in since I’ve been involved than in the past 50 years. We never used to debate offsides, we never used to debate handballs, we never used to debate holding in the box, we never used to debate so many things.

“I mean, did everyone really love the announcement today? Did that give you a real buzz? I mean, seriously. My understanding of it is, this is what the people want. That’s what I keep getting told.

“I understand that and I understand that VAR is going to be there. Technology is going to be a part of life, but it’s like my wife and our kids. We know technology but she limits their screen time. Why? You know, to slow things down, I think.

“We’ve just got to be careful about constantly… why do we want to change the game so much? And I know I’m going to be the old bloke in the stands that keeps shouting ‘boo’ every time and I’ll be the only one, but I just thought people would be a little bit more protective about the sanctity of the game.

“I think there’s a lot of confusion at the moment. That’s my belief, that the game is changing on the basis of technology, and I’m saying, ‘Why isn’t anyone speaking up about it?’ Especially in this country who, for all intents and purposes, you guys think you’re custodians of the game, you’ve got a song that says ‘It’s coming home’.

“This is your game, and yet it takes an Aussie from the other side of the world to be the one that’s most conservative about changes. I’m happy to just be the lone voice of saying, ‘Just leave the game alone for a bit’.

“Even extra time now, minutes added on, minutes added on here, we never used to talk about these things before. Yet now everything is changing, so that was my [point]. So today, I can see why Arne [Slot] would be very disappointed [with the Bergvall decision]. If that was me, I’d be disappointed as well, but apparently they’re the rules.”

‘I could be on a lone crusade here’

Postecoglou’s frustration stemmed from his anger last weekend when Newcastle claimed a 2-1 victory over Spurs despite a handball being missed against Joelinton in the build-up to Anthony Gordon’s equaliser, over which he described himself as “the angriest I have been in my career”.

Explaining how his anger had been misunderstood, Postecoglou said on Wednesday night: “My comments about ‘a fair and even playing ground’ that’s what they’re about. So today it advantaged us, yeah? I wasn’t saying that there was a vendetta against me or Tottenham when I spoke last week. That’s not what my comments were about. I could be on a lone crusade here, but I’m happy to do that.”