Let me suggest one under appreciated fact.
Most senior civil servants in the UK will be Oxbridge graduates with *decades* of successful career climbing behind them.
Those years of being at what everyone *says* are the best universities, followed by *decades* of shanking their rivals better than they have been shanked (thus demonstrating their superiority) make the idea that they might be ignorant about a subject (or rather they can get someone to study it for them and write a report they can judge effectively, which to them is pretty much the same thing) simply *unthinkable*.
Except in reality that is *exactly* what they are.
Just a thought.