I'm not convinced that setUpInfiniteScroll should be taking the event and the content profile data. It is possible that setUpInfiniteScroll is going to be called multiple times (new comment, comment searching later on) and it would be good to be able to continue using this function without having to pass the profile in again.

Assigning the content profile information to a widget variable should happen in the event callback, which then calls the infinite scroll function. This will be slightly more code, but should be more flexible.