I think BA, as the last carrier you flew, is responsible for delivering your bag and handling compensation. I'd ask for advice on the BA board to determine what they usually do.

Also, the connection time doesn't factor into it. If your originally booked itinerary was above the MCT, which it clearly was if in the end you made the connection even with a 50 minute inbound delay, then they need to sort out getting you and your bag to the final destination no matter how much time you spend on the ground on the day.