Straight after the game, Maguire went stick over carrot to begin the process of evoking the necessary reaction.
"Madge let us know about it," forlorn Kiwis prop Jesse Bromwich, who complied an impressive 158 metres through the middle, said. "We wanted to stick to our systems but we went away from that for about 10-15 minutes, and it cost us. We just weren't ruthless for 80 minutes.
"He was fairly stern which was warranted. We weren't there. We had the game right there by the scruff of the neck but let it go. The feeling in camp is they stole it off us. We thought we came here with a great attitude and put in a lot of effort.
"They scored a couple of lucky tries if you ask me but you've got to defend those; good teams do that."
Maguire's tenure, to date, reads this way:
One development test in Denver.
One inspiring victory over the Kangaroos.
One deflating defeat to England.
One more chance to get it right at Liverpool FC's Anfield arena.
"It's a lesson. All good teams go through this," Bromwich said. "The challenge is how you bounce back. If we lose that the series is over and we don't want that. We came here to win the series and that's still on."
Kiwis captain Dallin Watene-Zelezniak offered similar sentiments.
"There's two more games left," he said. "We can take confidence out of this game knowing if we get things right we can win. We keep saying we're young and inexperienced but we can't use that as an excuse. We're all professional athletes, we all play in the NRL, so we've just got to get better and turn up next week."
There were, of course, bright patches for the Kiwis; platforms they can build from. They constructed two quality first half tries but, then, didn't create enough chances to do likewise in the second spell and ultimately folded on defence.
This week's focus will centre on being much more clinical. As Bromwich mentioned, the biggest failing in Hull was straying from the plan of completion.
Too often, Shaun Johnson and others opted to run the ball on the last, allowing England an easy out.
The likely return of Adam Blair, who missed this match with a knee complaint, will also add vital experience to the pack.
But if the opening match taught the Kiwis anything, it's why two decades have past since New Zealand last won a three test series in England.
Passionate, vocal locals; dodgy refereeing, challenging conditions and dogged opposition make this a brutally tough tour. A true test of character, too.
There is no room for error. No time to clock off. And, now, England have confidence.
Two points decided this first test, and the next two could well be similar margins.
"It was important for both teams to play like we did today to show it is a full on test series," England coach Wayne Bennett said. "It's the best of three games and next week I have no doubts it will be tougher than it was today because New Zealand will desperately want to win.
"They will realise the importance of that, and we don't want to go into the third game with a 1-1 scoreboard."
From here, the Kiwis have it all to do.
