Not just BA. On my last flight with EK in F an unwell patient was moved into the empty seat next to mine. I approached the cabin crew to admit i was a doctor and although I had no particular wish to get involved I would be happy to help if they asked. As it happened they did wake me a little later to ask for my brief assessment to relay to the ground medical team. No thanks of any form offered (nothing expected except maybe a thanks from the purser as we left the plane but that didn't happen).
Rather ironically a complaint I made about very poor service on a flight a week earlier was dismissed by EK as I had apparently failed to acknowledge a medical emergency that all pax in F had been informed of by the purser on that flight (it was the first I'd heard of it)!