Have you lot never heard of 'Red Herrings'? Surely, Hastings taking his laptop to that shop is one. Immediately after the undercover cop and the woman had been in touch with 'H' on their laptop, we cut to the scene where Ted is closing his and wrapping it in bubblewrap. Having watched all the LODs so far, i am confident that writer Jed Mercurio wouldn't be 'showing his hand' this early if Hastings were 'H'. I believe the laptop incident is connected to the guy Moffat who is trying to involve Hastings in some sort of shady deal.