He probably thinks she got infected at a big Aleona Leonova's birthday party on Nov. 28th, Aliev was there too, and if i am correct, Gulyakova and Kolyada also... Aleona herself was wondering if that's what happened and posted "I was in close contact with Aliev but i am not sick". But, sources say Aliev has pneumonia not XYZ.
Леонова чувствует себя хорошо после общения с заболевшим Алиевым
Серебряный призер чемпионата мира-2012 по фигурному катанию Алена Леонова сообщила РИА Новости, что чувствует себя нормально после встречи с чемпионом Европы в... РИА Новости Спорт, 02.12.2020rsport.ria.ru
No, there was an article that said Liza felt sick before the Rostelecom gala (but she went ahead and participated ), and got tested when she got back to SPB. I can believe she got infected before she got to Moscow since it can take a few days to feel symptoms and to test positive. But just because the skaters didn't test positive before the competition, that doesn't mean someone couldn't have already been infected and clearly there were plenty of chances to spread it around there. They had to travel to the competition, stay in hotels, etc. and it's pretty clear that a significant portion of the public there doesn't properly wear masks.
I don't think the Mishin skaters were at Alena's party...but there were photos w/Gubanova, Makar Ignatov, Ksenia Stolbova, Nikolai Morozov and a few others.