Assuming a couple of comments are correct a few questions arise. It is alleged that the cabin crew were concerned and alerted the authorities. That would suggest that they by-passed the captain. It was alleged that the captain was covering for a colleague pilot. Surely, especially in BA, the cabin crew would first approach the captain. If he refused to take action they could make their displeasure known and refuse to fly. The captain could then strongly advise the pilot to call in sick and get off the a/c PDQ. In that case the police would never have entered the picture. Also, as this was a long-haul flight all crew members would have met for a pre-flight briefing and introductions. Surely any suspicions could have been voiced then and a SBY called out. It is quite a while before they arrived at a/c, when this matter erupted. It seems an odd course of events.