The articles say it was Kelley O'Hara, and definitely kudos to her. You can see even in that brief clip that she seems mortified that it hit the ground.
I don't think Allie Long dropped in on purpose, she was caught up in the celebration. But it seems pretty obvious to me that Rapinoe deliberately pushed it away and wanted nothing to do with it while she celebrated. That's certainly her right, but it's not going to win her any favor. Of course at this point, I'm not sure anything she did would be looked upon in a favorable light by those who dislike her stance.