I think you are right that initially there may have been a bit of friction if press reports from the time are to be believed.
But in my opinion one of the benefits of the present investigations although not joint ones has been the obvious breakdown of barriers between the Policia Judiciaria and Scotland Yard.
As a result it is my opinion that should any sort of international cooperation of any kind be required between Portugal and England or any other national policing agency in the future it will benefit from a better joint understanding of each others' working arrangements.
The Policia Judiciarua had experience of working with other countries before the disappearance of Madeleine McCann. Glen Pounder was well known to Amaral from his work in the area of drug trafficking.
https://wikileaks.org/plusd/cables/07LISBON1388_a.htmlIt was to Pounder that Amaral turned in the beginning;
It is urgent to know who this couple is, as well as their friends, what do they do, what problems do they have in the UK, have they ever mistreated their children, has a neighbour, family, friend or anyone else noted any inappropriate behaviour? What is their profession? Full time? Has anyone suffered depression? Is the marriage relationship healthy? Are they involved in any serious litigation? Does anyone hold a grudge against them? Why?...
These questions were delivered to the UK-Portuguese police liaison [on 4 May] who GA has worked with for years, Glen Power, asking him to forward the request, which the team considered "essential to the investigation" and waited for the response.
http://www.gerrymccannsblogs.co.uk/Nigel/id121.htmAs far as I know none of these questions were answered. Perhaps Pounder was too busy investigating boats seen in visions?
http://www.mccannpjfiles.co.uk/PJ/BOATS_VISION.htm