I agree with your thoughts. Even german tabloids are referring to english speaking press.
IMO, creating pressure is the key to that strategy.
So....HCW may know about english speaking people with knowledge. Either an accomplice what doesn't fit his statement that they are investigating just CB, or the key lies even in the tapas group, as GA assumed since many years.
It is a big hurdle to be part of a murder. But the hurdle isn't that big, being part of a burglary. It has been the first visit to portugal for the MC's, who shouldn't have been beggars so far? For how long did the tapas group knew each other and has anybody of them been in PDL before?
And the reported "horrible job" statement, if true, is still in my mind.
IMO that isn't a brexit-thing.