I have been told the following this morning by a music distributor:
I do £millions of sales to amazon, all buying & marketing negotiated and run through Slough, never heard anything from Luxemburg. The retail / buying management chain went Slough > Seattle to my certain knowledge.
Meanwhile, in contrast, iTunes ‘buyer’ was indeed based in Lux.
What I have also learned is that he told HMRC this in detail in 2010.
HMRC have questions to answer in that case. Why didn't they act if they had this evidence?