I'm wondering if Rossi is worried about Hotch and how he will handle things when they finally confront Foyet. He's known Aaron longer than any of the others
and can probably 'read' Hotch better than they can and thus knows exactly how upset Hotch is by this whole thing with Foyet. And he might be a little upset with him about being so stubborn about things, too. On the other hand, I loved their little snark-fest in the last scene on the jet. Made my little Hotch/Rossi shipper's heart sing! (Something from the "White Album" not Frank or Dean.)