With hindsight I don't think you can unequivocally say that Brown did the right thing. Bailing out the banks through QE was a terrible terrible decision IMO.
I think swift action to prevent the collapse of the entire banking system was absolutely the right thing to do, and I don’t think there are any serious economists who’d disagree. The subsequent policy details are more controversial.
And Brown actually did the right thing and stopped the banking system collapsing. He was out of office within two years.