Starting to make a little more sense.
How does Qrow not recognize those guys as the attackers, though?
He was focused mainly on Cinder, and saw Emerald and Mercury for just a moment. And he was definitely most concerned about seeing to Amber's safety, as opposed to memorizing their faces. Even with that, though, he still does know that they are at Beacon and did bring it up to Ozpin earlier, although he hasn't actually come across them at Beacon yet. He'd only have seen them in the tournament, and he really doesn't seem to care much about watching that.
I hope he watched Yang's fight though, and remembers Mercury. Might help clear her innocence up a bit.
And I hope Pyrrha learns about Mercury's legs. Magneto? Magneto!