Third-placed Norris believes that he could have deprived Leclerc of second in Melbourne if McLaren had have gone for an undercut strategy, as Ferrari and team-mate Oscar Piastri did.
But when this was put to Stella, he implied Ferrari won out on merit because the SF-24 is a faster car than the MCL60. The Italian added that a team orders call to swap Norris and Piastri was about minimising the risk of the pair crashing rather than fully believing Leclerc could be caught.
Considering Norris's claim, Stella said: "It's possible. It's possible. That was very, very early in the race, a race with a high degree of uncertainty as to the behaviour of the hard tyres.
"And in fact, we saw that there were certainly some big cars that didn't look quick at all because they were not working well with the tyres - one is the Red Bull of [Sergio] Perez [who finished fifth].
"So, I think we actually went for this aggressive strategy, trying to pass Leclerc with Oscar. But Leclerc decided that it was a good idea as well. And they went at the same time - potentially, because of listening to our radio.
"This also meant that Leclerc and Oscar would have gone below two cars fighting each other.
"So, with Lando in a strong position, we thought that was an unnecessary risk."
Stella did soften the blow, adding that although the Ferrari was quicker, it was only marginally ahead of the McLaren, which is bringing an upgrade package for either the Imola or the Miami GP.
"Leclerc finished ahead of Lando because they have a faster car at the moment," said Stella.
"The positive news is that this faster car is not faster by much at all. We were very close, which I think is encouraging for Japan in which some of the characteristics that make Australia good for us take another step further in having a higher ratio of medium-high-speed [corners] compared to low-speed."
On the decision to swap Piastri behind Norris at the former's home race, Stella explained: "I would say that swap wasn't even strategic. That was executional.
"The swap would have happened naturally because Lando had much fresher tyres… We called the swap to avoid that this comes to unnecessary racing …
"But despite having fresher tyres, actually, we didn't catch Leclerc enough. This is why I'm saying Ferrari were quick today."
