What was Gordon Brown thinking?

He really did say this at PMQs:

I do accept that in one or two years defence expenditure did not rise in real terms.

Cameron, who looked astonished at Brown’s admission, responded:

In three years of asking questions I haven't heard him make a correction or a retraction.

Brown’s evidence to Chilcot will now have to be corrected, which presumably means he will have to return to the Inquiry.

And there was something else.  Cameron called Brown “weak”, invoking memories of when Tony Blair called John Major, “weak, weak, weak”.

Brown looked and sounded like a forlorn man today.

With his evidence to Chilcot unravelling, the strike and the exposure of Labour-Unite link, one has to wonder if Brown regrets not calling the March election.