If this is the MCO-LGW incident that were talking about then as a crewmember based on this fleet I was under the impression it was a crew member that was injured (infact I trained with the lady in question and she was back flying pretty quickly after the incident) and she told the captain that she was able to continue.
We must remember here that this was not some BA policy the made the aircraft continue. Dozens of BA flights make emergency diversions for illness each year without the company questioning it. Its always the crews first priority to ensure that they are doing the right thing for the sick/injured person. Infact, usually it is Medlink, a company BA subscribe to who offer inflight medical advise to crew from their base in Phoenix ( or is it houston, i cant quite remember) and they usually advice whether a diversion is strongly advised or if the condition should be ok for the flight to continue. They will then take charge of arranging medical assistance to meet the aircraft should it divert or continue and that also includes advising the hospitals!