When Tom Fontana was a producer on the show “St. Elsewhere” in the 1980s, he loved to push the boundaries of weirdness that he could get away with on network TV. For instance, he staged a crossover with “Cheers” — a sitcom — but they shot the sequence like a drama. And he pulled one of the strangest trick endings in TV history. In the series finale of “St. Elsewhere,” we learn that the entire show had been a fantasy of a boy with autism named Tommy Westphall. These shenanigans didn’t go unnoticed by fans like Keith Gow, a writer in Melbourne, Australia. He wondered if every show that Tom Fontana produced or staged a crossover with could be connected back to the finale of “St. Elsewhere.” In other words, did Tommy Westphall — the kid who dreamed up the characters on “St. Elsewhere” — dream up all these other shows as well?