Pirro explained that the FIA had warned Hamilton's Mercedes team earlier in the race about exceeding track limits, even though the teams thought it wouldn't be policed in the race in the way it had during practice and qualifying.
"Hamilton went over the track limits a little too often, creating a repeated advantage," Pirro said. "That's why [FIA race director Michael] Masi, the only one with the authority to talk to the teams, called Mercedes to warn them that if Hamilton did it more often, he would get the black and white flag."
You would have thought exceeding the track limits 29 times in a 56 lap race met the meaning of "more often" but it seems not as far as Hamilton was concerned.
"I thought there was no track limits," Hamilton told his race engineer Pete Bonnington on the radio, after receiving the warning.
"Yeah, copy that on the track limits Lewis, but we're getting the messages from Race Control so you will get a black-and-white flag next time. Then five seconds."
Hamilton said this was "bullshit" during the race and later said, "it was very confusing".
"Most tracks we're not allowed to put four wheels outside the white line but this weekend on that particular corner [Turn 4] we weren't allowed to on Friday."
Pirro also confirmed there was no doubt Verstappen would have been punished, as the rules were clear.
"There can be no misunderstanding there, according to the sporting regulations paragraph 27.3 it is very clear. You cannot make an overtake where you go over the track limits," Pirro stated.
"Verstappen did, although he didn't do it on purpose, he simply went a bit wide. At that point Masi warned Red Bull and advised that Verstappen could give his position back.
"A race director will never oblige anything, because he is not allowed to, he can only suggest. Verstappen gave the spot back and we no longer had to deal with the case specifically."
McLaren driver Lando Norris, who made a great start to the new season with a fourth place finish in Bahrain, albeit 46 seconds behind the winner, doesn't think Verstappen deserved any penalty.
"I don't think Max should have had a penalty, because he did the overtake before [going off track].
"Look, he's miles ahead of him," Norris noted. "But Max then just has a big oversteer. If Max just lifts and doesn't commit to full throttle, he could have stayed on the track. He has oversteer when he is already ahead and then goes off the track. In my opinion, he doesn't complete the overtake by going off the track."
What is clear amongst drivers, team personnel and commentators is that the track limit rule is confusing and questionable.
Ross Brawn was pleased that Verstappen took heed of the warning as he felt it would have "left a nasty taste" if he had won the race breaching the rules. But Sky Sport commentator Martin Brundle questioned how you quantify a 'lasting advantage' unless it's clearly involving a pass?
"We really do have to police this issue consistently everywhere and not just in qualifying. It's confusing and annoying for everybody, including teams and drivers I've spoken post-race."
McLaren team principal Andreas Seidl says the ruling needs to be "monitored consistently and policed consistently in the same way".
Mercedes boss Toto Wolff has acknowledged that Masi's decision actually won them the race, but also says consistency is required and the messages given "need to be clear" and "not a Shakespeare novel that needs interpretation".
Clearly there is something wrong if Hamilton can exceed track limits 29 times and go unpunished. Despite that, former world champion Damon Hill thinks it was one of Hamilton's greatest drives.
"He never looked like a favourite all weekend, he didn't look like a favourite from before the launch of the car," Hill said. "There were people who put money on Max Verstappen winning that race, but Lewis stopped the rot and that was an exceptional performance under pressure, being hunted down, but keeping his cool.
"And when Max pounced, Lewis still had a couple of tricks up his sleeve.
"Max Verstappen, the young pretender, against the established seven-times world champion going for his eight, Sir Lewis Hamilton, who was on spectacular form. I think Max will look back at this race and think about how he could've done things differently, but nevertheless, he got suckered in. Lewis absolutely sold him a dummy, and he went for it," Hill suggests.
"It looked great going round the outside of Lewis Hamilton, very tempting offer, thank you very much, but of course Lewis knew all he had to do was use up all the track and squeeze Max.
"And then Max had the pressure on him, as we know he had to give it back and maybe gave it back a little too soon. He will be going home now and actually thinking to himself 'damn, damn - I shouldn't have done this. I shouldn't have done that.'
"Lewis meanwhile will be thinking 'gotcha'. He's still got a few more things to learn.'"
Hill's analysis may be correct, given this was really the first time a race has come down to a straight battle between Hamilton and Verstappen.
Former three-time world champion Nelson Piquet says if Verstappen was driving a Mercedes, he is "sure he would smash Hamilton".
"Max is more aggressive. He may make mistakes more frequently due to this aggressiveness, but in my opinion he's better than Hamilton," Piquet says.
"Things are too easy for Hamilton to win it all with [Valtteri] Bottas by his side as a second driver. It's a bit like Mansell and myself at Williams, with the other drivers far behind. I won the 1987 championship and I wasn't driving like before because I had an accident at the beginning of the year and had field-depth problems. But I won that championship with a bit of luck.
"But it was so easy - the car was far better than the others. And Mercedes is far better than the others for the past years."
Piquet probably didn't feel it necessary to disclose that his daughter, Kelly, is Max's girlfriend, and he is maybe a little biased!
Meanwhile, Mercedes boss Toto Wolff has accused McLaren boss Zak Brown of "spreading s***" by predicting Russell and Verstappen will drive for Mercedes next year.
"You will see Max and George there in 2022," Brown says.
"Brown is like Christian Horner," Wolff reportedly said. "They just spread s***. I think Zak wanted to give Christian one with it. I don't care."
Wolff also denied being aware of a rumour that Hamilton and George Russell, the Mercedes driver on loan to Williams, are no longer on speaking terms. Russell replaced Hamilton for the Sikhar GP last year when Hamilton had coronavirus and demonstrated he was better than Bottas and could drive a car he didn't know, as well as Hamilton.
Speculation of who will drive for Mercedes next thing shouldn't detract from what appears to be a genuine battle between two drivers in different cars.
Hamilton says he "thinks it's something fans have wanted for a long time".
"Of course, this is only one race, so we don't know what the future holds. With the pace they [Red Bull] have, they could be ahead a lot more, but we're going to work as hard as we can to try and stay close in this battle."
