After winning the first Test in Mendoza a week ago, France were sent into a spin by two seperate scandals that rocked the camp and robbed them of three players.
Forwards Hugo Auradou, 20, and flanker Oscar Jegou, 21, were arrested on Monday and formally charged on Friday after a woman accused them of raping her multiple times and beating her in a hotel room in Mendoza after last weekend's Test.
The players have denied the accusation, and say sexual relations with the woman were consensual.
Serin's side were also without full-back Melvyn Jaminet after he was removed from the squad last Sunday for making racist comments in a video on social media.
"It's been a very complicated week," said Serin after the 33-25 defeat which left the series tied at 1-1.
"But it was an international match and there was only one thing that motivated us, only one thing we could control, and that was what we could give on the pitch.
"And we gave it everything we had."
Coach Fabien Galthie spoke on Friday of "a trauma" within the camp but said post-match that the French had worked hard to try and get the win.
"We had to deal with it, we had to work together," said Galthie.
"We had to do it for the match, for the group, for the delegation. We put a lot of energy into this work, this commitment, throughout the week.
"We really wanted to win. There are a lot of things to remember from a defeat. We took the knocks, but the players reacted really well in the second half. They can be satisfied."
'Stand together'
Theo Attissogbe, who played with Auradou and Jegou in France's World Cup winning Under 20 team last year, said the arrests had had an impact on the squad.
"Inevitably, it wasn't an easy week," said the 19-year-old Pau wing who made his debut in the series, scoring in both Tests.
"We tried to put up the best front we could, each in our own way because everyone is different. We tried to do the best we could, to stand together, to pull together.
"And that showed in the match. We tried to put in a huge commitment, a huge fight. I'm not saying it was easy but we did our best."
His clubmate Emilien Gailleton, meanwhile, admitted that it was going to take time to get perspective on events of the past week.
"Of course it's complicated. I think we're still having trouble realising it because we were still in a match week where we were trying to concentrate," said the 21-year-old centre.
"I hope I'll manage to make the most of my holidays and not think about it too much, but maybe over the next few weeks we'll really start to realise it.
"This is my generation. We don't know how things will turn out, we'll just have to wait and see."
Auradou and Jegou remain in custody until a hearing to determine if they will await trial in detention or under house arrest.
If found guilty, the players face between eight and 20 years in prison.
