Raheem Sterling was denied that injury-time goal against Tottenham and Guardiola's interaction with the winger after the FA Cup's final whistle on the Wembley pitch was so instructive to the relentless mentality that makes him and City so formidable and frightening.
It never stops. As the streamers laid strewn and the celebrations carried on, Guardiola lectured Sterling about something he had seen the player do not to his liking. Sterling scored twice, many thought he had completed a hat-trick, and here he was being micro-coached before a smile and hug.
It was reminiscent of Guardiola doing something similar to young Bayern Munich defender Joshua Kimmich in the centre circle after a game against Borussia Dortmund and cynics argued that — and will extend that to Sterling — was the manager playing up to the cameras. It could not be further from the truth. Guardiola is caught in the moment.
"It was something in the second half, one action and I said I didn't understand him [Sterling], he didn't understand me, that's all, nothing special," he said. "I listened to what he thought, I said my comment and that's all. It happens quite often in the training ground, the locker room."
But, still, not usually on the pitch, not usually after a final and not usually at the end of such an amazing campaign. But as ever for such an intense coach, it felt like there was no time to waste.
"I wouldn't be here next season unless I believed we could improve as a group. I know it will be difficult because people will compare and people cannot expect us to repeat the treble or four titles in one season, that is something one team does once in their lifetime," Guardiola said. "I'm not focused at the start of the season thinking: 'I have to win one title, two, three or four', never."
Even so, the Champions League, which Guardiola has not won since 2011 and City have never won, will loom larger for a club and manager looking at ways of breaking records and making history. Despite the denials.
That is if they are allowed to compete in it, and if a ban is confirmed for Uefa Financial Fair Play breaches, expected to come into force the season after next, it will concentrate City minds even more in needing to win it while Guardiola remains.
Interestingly his contract runs until the end of the 2020-21 season, which — if there is a ban — means he will have one more tilt unless he signs another extension.
Such talk exposes the gulf that exists between City and a club such as Watford who were in only the second FA Cup Final of their 121-year history and aiming for their first trophy. They have had an excellent season, with a good team and led by a smart coach in Javi Gracia who came with a clever tactical plan and raucous support but was left drowning in City's utter dominance.
Maybe it would have been different if Roberto Pereyra had taken an early chance, only to be denied when through on goal by the alertness of goalkeeper Ederson, but that was a big maybe as City overwhelmed them, with Bernardo Silva, Gabriel Jesus and Sterling impressive. It was a master-class in tearing a team apart and all the more scary because of the occasion.
