It's a Daily Mail "two thirds". Ie. Not necessarily connected with reality.
I see from another thread that the Daily Mail is reporting the diversion was due to a "disruptive passenger", yet in this thread it was reported as 2 medical cases. I know which one I would believe!
Incidentally, there's not much wrong with the route. Whenever I am back on home turf, it is quite normal to see the Emirates & Qatar flights from NY go overhead the Wirral, usually early morning.
For example; yesterday EK236 from Chicago to Dubai flew that route, crossing the Wirral at around 08:15. The Etihad flight from JFK followed 20 minutes later with flights from the US to the Emirates following in quick succession.