Was race the problem when BA denied me boarding?

I was the only one of our group not allowed on a connecting flight and BA won't tell me why I attended a conference in Portugal with some work colleagues. BA operated the return Porto-London leg and Finnair was to fly us home to Helsinki. The flight from Porto was slightly delayed, leaving us just under an hour to reach the gate for our connection at Heathrow. Passengers were still queuing to board when we arrived. My wife and colleagues checked in without difficulty, but, although we had all ar...