I can't find an official apology to Cambodia in Hansard, any idea which year? There was a debate in 1991 in which Thatcher denied involvement and later ones 2000/2004 where involvement was admitted.

As for the Balfour agreement, it was deliberately vague and hinted of a Jewish protectorate within Palestine rather than a state that replaced Palestine. The support for a Jewish state was later in the Paris Peace Treaty 1919 and later conferences in 1921 when Churchill was Secretary of State for Colonies.