There was clearly some bad blood between Sherlock and Howard. Joan remembered how Howard spoke of John with some fondness, and then with Sherlock with quite a bit of dislike. She wondered what had happened to cause that (apparently mutual) dislike, and wondered if Howard's interest in John had something to do with it.

Now was hardly the time to ask, though, so she just looked at Sherlock and waited for him to explain his query about jumping dinosaurs.