Okay so I'm rewatching episode 1 and I noticed something..
So Viktor is the competition doing Stay Close to Me while Yuuri is doing the same skate back in the Ice Castle rink in Hatsetsu at the same time (because the way the POV switches from Yuuri to Viktor and vise versa throughout the entire skate is to show they're doing it alongside one another even though they aren't together) ^assumption^
Well the second quad in the Stay Close to Me routine is the quadruple flip, which is Viktor's signature move. We can assume Yuuri can't do a quad flip because the times he is shown to attempt it in the competitions he touches down or just gets in enough rotations (minus episode 12 when he finally lands it).
But the thing is, after the skate is finished and Yuuri looks over to see Yuuko's reaction, she freaks out (same) and says it was a "perfect copy". In order for it to be a perfect copy like she says, that means doing every part of the routine exactly as Viktor did it (if that wasn't obvious), including landing all the quads.
So does that mean Yuuri landed the quad flip right there in episode 1? No clue. It just got me thinking about what else it could mean if he definitely didn't land it (because she didn't say "nearly perfect" or "almost perfect". She said perfect, period.)
Sidenote: LMAO @ Yuuko's face in that picture. I feel you fren ;-;