Familiarity with UK procedures by US crews stationed here is a constant challenge. There is no OAT equivalent in the states & no direct correlations for RAS/RIS - this is hard to get one's head around when first landing on island here & is a continual education process.
As a gross generalisation, the under-educated typically believe any radar service is the same as in the states where the controller, while vectoring you, has responsibility for terrain clearance. Whilst ultimately, the pilot is always responsible for everything even in the States, a great deal of trust is placed with US ATC controllers.
The Eagles in question, bet their life on an assumption. That they were wrong is tragic, not stupid. We owe it to them to not repeat their mistake.
I don't much care for witch hunts - it serves little purpose. Whether he is culpable or not, that controller will live with doubts that he himself must deal with - even if found in the clear & had done everything by the book. Punishing him is nothing more than leadership through liability control...