How long would it delay the flight if the family had pulled the plug once every one had boarded and decided that wanted to be put on another flight? Also it may be BA's policy, but it BApremier who is the cause of the problem, as he has taken the fathers seat. What I would like to know from some of the crews is are they told that a certain passenger has been downgraded, and to try and make him feel more comfortable and appreciated in the lower cabin. In the situation where a family has been split up would the father have been allowed to go and see them during the flight?

I do not think that it was rude of the family to comment on such a situation! To me it is more ill mannered to think that money can buy you anything, and that being someone else's prebooked seat!