True, I have also see it done to men. Usually juniors.

It is because it works for them. They get credit as if it was their idea. Or sometimes people react as if it was a shared idea, not from the person who said it.

It can even happen in writing. You put something in a mail or a document and yet, they try to claim credit for it.

And sometimes works while there are no real consequences for doing it. No one would think less of them. So they have no reason to stop.

I guess one way to expose them is malicious compliance. I mean, you can pretend to go along with their act and ask them questions instead of adding more information. Since they just repeat and parrot but many times doesn't really understand the idea, if you, the one who really had the idea, ask questions, you push them into a corner.

So instead of saying "It was me who get the loft". Ask him publicly how did he get such a good deal, that it must be really difficult and that you want to know how did he do it. That would put him on the spot, which is uncomfortable. And the more they talk without someone giving them cues, the more likely they would expose themselves as liars by saying things that doesn't add up. And if you want to be even more petty, you can answer the question when they fail.

As you can guess, it also have happened to me enough times that I had to think of a polite solution (not gracious though).