Yes, this deadgame getting revert would be defavorable to my team, does that mean I have interest in arguing over your deadgame being reversed? yes. Does that mean I'm trolling? no. Can't I geniuly believe you messed up? Yes, I totally can.
You're speaking about good manner to justify not making an activity call earlier, so I'm gonna tell what else is good manner: respecting the deadlines, that applies to everyone and everything the same, being playing games, making act call, etc.
Another good manner is also as a manager to make yourself easy to contact for everyone and to be transparent on your actions with other concerned managers, which you are the most responsible for not respecting. Mutliple managers had issue contacting you when they had difficulties with your players.
Like do you think your team being involved in 4 games not played, while needing wins to clinch play off, is a coincidence?
You don't want act win, that's in your honour, but let's not act like you didn't have time between the games deadline and the act call deadline represented by the host posting their decisions, there was a full day.
Also, asking for an activity now is basically refuting France the possibility to make another sub to cover up for it, which is basically A) the biggest act fishing you could ask for, B) makes it technically unneligible for an activity win according to this ruleset:
https://www.smogon.com/forums/threads/tournament-rules-and-general-guidelines.3642760/#post-8529717
Moreover, as mixwell (yes he is in team argentina and just like me would get ejected over this decision being reversed, does it means he is wrong? no.) highlighted, extension in teamtours are a rarety, and you're talking like it's the standard to justify yourself. (plus again, you had a full day to check with the hosts before they took any decision)
Finally, I don't exactly appreciate being called a troll when I point out that you are the one to blame for that decision. Regardless of what you consider good manner, some things are factual, like deadlines and guidelines, and if because of your good manners you are able to get this reversed, it would just be unfair for every other manager that dealt with it respectfully of the deadlines and guidelines.
And, calling people that don't agree with you trolls is not really what I'd call a "good manner" either.
Tl;dr: Considering your behaviours toward the deadlines, guidelines and other managers, I, personnaly, don't think you're in position to talk about "good manners", but I'm just a biaised manager so what do I know.
Anyway Gl in your remaining games, be it in a tie break with Argentina, China and us, or in play-offs if you get what you want. And sorry for any potential cringe to any one reading that full post.