I would hazard a guess that, the main problem here - is lack of airspace education given to the US Crews that arrive in the UK.
We have some very crowded and complicated airspace for them to navigate and they obviously need some help here!
It would appear that reading between the lines, that they used to get a thorough briefing from the RAF in years gone by to indicate the differences in UK airspace and how the RIS / RAS effect their flights compared to that they were used to in the USA.
Bring that briefing and education back guys.. It's got to be worthwhile and will help them out!
However, with regard to the latest airmiss; it would appear that there were many links in the chain that lead to a major cock-up.. Lakenheath ATC caused a further problem with the lie about no delay and did not pass full details of squawk and Flt Level restriction from Lon Mil.
When the Flight lead decided to divert he should have positively taken back the Flight lead role and have his wingman understand that and act as a flight and not two singletons / loose flight.
All this time, what were the Wso rear seater crew doing to help? It appears they were just along for the ride! It doesn't appear that they were helping much. Do they not have a role in helping monitor the flight and assist the pilot with Nav etc. Obviously they could be head down and use the F-15Es kit to help the situation.
Finally, was RAF Valley really the nearest suitable diversion airfield for these two aircraft?
Perhaps, with the rapid closure of RAF bases around the country; suitable diversion airfields are becoming very few and far between!