Yeah, I didn't think about it until after the episode was over because everything was so intense. I suppose I could make it work in that maybe John didn't know what hospital she'd been taken to and was hoping someone would know, or that he'd been called at the same time as the ambulance and he thought he could get there before the emergency people did or something. I know it's a nod to the original story where Watson gets called back to the hotel for a patient, but it still doesn't make much sense.