AFAIK, it will be about whether he had the legal right, in view of his former position, to state what he did, when he did, and present it as fact.
His appeal is likely to be that he was technically free from any former professional obligations to shut up. There does seem to be a grey area over when this shut up period may be considered to have ended.
On the other hand, it's impossible to launch a book, ready to go on sale, 3 days after the archiving despatch had been made public without those involved in the publishing industry being aware of the contents. *
That is likely to be part of the issue... and if there are no precedents, it may be complicated.
* ETA: he therefore breached the confidentiality regulation while he was still a serving officer.
His objection is likely to be that this breach is of a lower order (an administrative offence) than his constitutional right to full freedom of speech.
I think (now!) what the judge meant when she said she is not interested in questions of truth or untruth is that it was not her job to test the truth (or otherwise!) of
the files themselves.
Her job was to test to what extent Amaral's book reflects what is written in the files.
If it's in the files, Amaral can say it (and not be touched in libel) even if it is demeaning to the McCanns.
A complication is that stuff written in the files is contradicted by other stuff, also written in the files.
It is written in the files (Almeida!) that Eddie
scented death all over the place.
And it is written in the files (Grime and Harrison) that no incriminating inference can be drawn from the reactions of the dogs.
So does that entitle Amaral to say Eddie
scented death?
Or doesn't it?
In my view, it ought not.
Amaral completely misrepresented the role of Harrison (as written in the files).
That ought to be a very big black mark.
And Amaral's last chapter contradicts the archiving dispatch.
That should be the biggest black mark of all ....