Justin, the context in which the sentence Marin is quoted for was said. The interview, the questions leading up to this. They were talking about the match, and how Marin felt during the match "at which point she felt she would win".
It's got nothing to do with translation, but simply it's a matter of reading more than Marin's statement alone. And the first quote's and translations provided, did not convey the context. Somewhere in the links, I found the actual interview, and then I wasn't in doubt - it was not speculation - she was of course talking about her mindset during the match, and explaining why she acted the way she did (played 100% full out to win).
I don't have the time to go further into the details here, and backtrace all the posts, etc. So I can't really convince you further.
And would we have done what she did? I don't know. Do you mean if we would have played full out to win, or mention the thing in the interviews afterwards? As for the match - if you play for a medal in the Olympics, you play to win. If your opponent keeps playing, you give it your best. You cannot hold back, because you think your opponent might be injured - that's a decision for your opponent to make. If you're injured, you stop playing. If you play, you expect your opponent to give her best.
Then, after the match, it's something else. you of course show good sportsmanship and behaviour towards your opponent.
It's difficult about the "cheering" part. Because even though, at the end of the match you might win because of an injury, you still have reached your goal for a long time, are thrilled about that, and you celebrate not just the final few points that came because of the injury, but you also celebrate all your efforts gone into this over the past months. You succeeded. You would have liked to get the final points in a different manner, no question about it, but nevertheless, you managed to win and reach your goal. The first parts of the match was won fair and square. The other matches likewise. So you're happy.
I think, personally, I'd have dampened my self a bit. Gone to my opponent, and talked to her, showing my respect. Then I'd had gone back to my own court, and cheered for the result and accomplishment.
I mean, Ratchanok didn't make it to a medal. All that she failed to do, Marin succeeded in doing. And that had nothing to do with the injury at the end. So there is a sense of relief and a reason to rejoice once you are at the goal line.... It's a difficult balance I guess.
As for the interview, I'd probably have kept it to myself. But I think it's a fair statement, to explain why she was playing full out on court, even though on TV it seemed that she had a certain win. She is not saying that she thinks after the match, the injury was faked.