Good article Jane, thank you. What is doesn't say is whether this data is anonymised, which anyone can see anyway, pseudonymised, which despite promises to the contrary can be joined up for identification purposes, or data in the clear.
I am relieved that CAG is at least still in operation, I had heard rumours it was being abolished, but perhaps sidelined would be more accurate! 
The need to treat each other's patients had led to the sharing of GP medical records across areas, with access being given to researchers too. Some are properly asking for the patients consent at the time, others are ignoring this requirement. I did ask if a previous opt out to the Summary Care Record (SCR) would be taken as applying to this data sharing and received the reply that they presumed it would.
I take it you are in discussion with Phil Booth of MedConfidential on this one? 
medconfidential.org/ is worth a browse for others reading this.
In answer to your question' does it matter', it depends on whether the data is truly anonymised (just figures) or not. Yes it most definitely does matter if data is being shared for purposes other than that for which it was collected. Most people would be happy to 'donate' their data for research if asked, but there are others who have good reasons for needing to keep their records private.