2:19 is where YoonA hurt her leg she keeps performing but she's visibly hurt and hops offstage after its over. She was absent from the fanmeet for awhile too. And you can tell Taeyeon is sick from her movements or lack thereof.
This was the same day as that interview btw.
That gotta hurt!
and yeah I saw the interview stills, I'm pretty sure they weren't jealous, they would've disbanded long time ago.
however, the interview was indeed so awkward. interviews go different in the US, they have to loosen up a little.