Another person said: "What the hell is he doing behind the president's back".
And in a final irony, Trump cancelled his scheduled press conference at the end of the summit, concluding not unreasonably that he had already said all he had to say during his ad hoc Q&As.
The clip went viral yesterday while Mr Trump was having talks with his fellow leaders.
Trudeau could be heard saying "he was late because he takes a 40-minute press conference off the top".
The ad marks the continued fallout after Mr Trudeau, French President Emmanuel Macron, British Prime Minister Boris Johnson and other dignitaries were caught on camera engaging in a brief exchange apparently about Mr Trump that quickly spiralled into an global incident. "You just watched his team's jaws drop to the floor", Trudeau also appears to say at one point in the video.
In his wake, Macron, Johnson and Trudeau scrambled to wriggle out of their embarrassing diplomatic blunder where they mocked Trump behind his back. Using that footage, combined with previous embarrassing moments (including the time he got laughed at during a United Nations speech), Biden's team released a new and devastating ad calling Trump "incapable of world leadership".
He has condemned as "nasty" Macron's criticism of North Atlantic Treaty Organisation as brain dead, branded European countries that have failed to meet military spending targets "delinquent" and railed against moves in Washington to impeach him.
Reporters today asked Trudeau if he apologized over the video.
"And honestly, with Trudeau he's a nice guy, I find him to be a very nice guy but you know the truth is that I called him out on the fact that he's not paying two per cent and I guess he's not very happy about it".
"With Trudeau, he's a nice guy".
However, that doesn't seem to have appeased the Trump side, and on Friday Trudeau was taken to task by Trump's 2020 campaign manager Brad Parscale. His complaint has been that some of NATO's 29 members are not spending two per cent of their Gross Domestic Product (GDP) on defence, as agreed in 2014 as an indirect response to Russian aggression in Crimea. Says reference to "jaws dropping" among members of president's team was about unscheduled announcement that U.S. hosting next G7 at Camp David.
The question now is whether Trump is "not very happy" with Trudeau.
The daily Presidential Tracking Poll by the Rasmussen Reports finds that 52% of Likely U.S. Voters approved of President Trump's job performance as of Thursday, up from 49% on Wednesday, and reached the highest level since September 24.
The irony was not lost on Trump.
He said it was "sad" that Democrats were pushing the inquiry when "there was no crime whatsoever and they know it".