So this isn't really about the characters in Hisui so much as the Pokemon left behind, and I guess depending on what's going on back there this could theoretically be irrelevant, but.

Say the Pokemon of a trainer and a breeder who live together in the same house decided to get together and make some eggs while their people are stuck in Hisui, so that when they get back they'll have a deluge of eggs to deal with. If two of the breeder's Pokemon got together, would this count as under the supervision of a breeder (for the purposes of shiny chance/hidden ability caluclations/etc) even though the actual breeder is away? What about if it was one of the breeder's Pokemon and one of the trainer's?