Thank you Capn Bloggs. Words of wisdom. Happy to share my faults, take the blame and kick in the gonads to make aviation safer.
One thing I missed to say earlier was we were subsequently asked by the controller if we were in sight of the surface, and yes we were. The ground was more than 5000ft below us. Have a look, it's flat with no charted spot heights or obstacles. Granted there's a restricted zone there. I cannot find any info on it. But if it was not active at the time then safety, by luck or otherwise, was not compromised.
I will make it my mission to write to the Spanish to get confirmation of their expectation and what the correct phraseology from them should be when on a direct routing to somewhere (like DIXIR) that does not have an explicitly defined altitude/FL restriction like for example VIBIM does. Will report back, I suspect in 90 days
