"In his role as Secretary of State for Constitutional Affairs, Lord Falconer sought to make it easier for government bodies to refuse to release documents under the Freedom of Information Act (2000), "
Source : http://en.wikipedia.org/wiki/Charles_Falconer,_Baron_Falcone...
Alternatively he might be angry that the overly broad legislation that he was involved with has been used an imperfect way and justified the criticism that it received. I lean a bit further toward getting one over on the Tories though.
Put specific cases in which the law is applicable into the law itself, and specifically exclude as many applications as you can see that it shouldn't be applied for.
Giving broad powers to police and trusting them, just like trusting any human with broad powers, is a recipe for disaster. But then again we all knew this, I'm glad it's been an eye opener for him.
If this was a misapplication of the law then all that's called for is a slap on the wrist for the people who detained Miranda and an official apology. They might get some extra oversight out of it, but that's a stretch. Probably just a few internal memos so future actions don't raise such a stink.
The government doesn't comment on security matters. There is no recourse. End of discussion.
He's very much the type that might take this type of abuse as a combination of personal affront and horrible insult to the legal system, as well as worry that abuse of this law will reflect badly on him.
And he's not exactly best buddies with Theresa May.