Bongo,
Firstly, if you believe that the captain in question deliberately lied to you about the safety of the aircraft, and proceeded to endanger you in some way --> then I suggest you think again. A skipper flying an A330 with a mainline UK fleet will have a lot of experience, will have paid a fortune for his license, and will have a lot to lose financially and legally if he gets it wrong and breaks the rules.
I don't know about this incident specifically, but it sounds like he had a tech problem which didn't allow for ETOPs operation (Extended Twin Operations). This means that he was not allow to stray more than X miles from a suitable airport due to what ever tech problem you were carrying (i.e. no direct Atlantic routing).
He could only have carried a tech problem if there was official 'relief' available for the system affected. Any change of routing will have been looked it in great detail by the ops/planning dept ...etc...
This type of event is common, and the extra routing would have required extra fuel, which required the offload of some of your baggage.
We all (as pilots) deal with these types of problems all the time. More often than not, the action taken is to satisfy a legisitlive problem rather than a physical technical problem.
The reason you landed safely (I would suggest), is because the flight was conducted safely ...