I agree with those saying that trying to identify the reviewer would not be helpful.
If people try to name the reviewer, then it becomes all about the reviewer, and how terrible he/she was. If we ignore the reviewer's identity and focus instead on the endemic problems in the pro-PACE community, and the the BMJ's tacit support of it, then its a much more powerful argument.
Looks to me that this reviewer is trying to provoke this sort of response (outing the reviewer), in a desperate attempt to smear and distract and obfuscate the real issues and problems.
The content of their review makes it abundantly clear that they got nothing else up their sleeve, and that they know it.
So don't give them the response they are hoping for.
No need for us to get our hands dirty on this one.