Terror trousers

David Spens QC shows a nice line of legal reasoning but little grasp of idiom, as reported in the Bristol Evening Post:
"Was he an Islamic extremist intent on carnage and mass murder in the heart of Bristol?" Mr Spens said. "Or was he a weak, lonely figure, living much of his life in a fantasy world, pretending to be somebody he is not. All style and no substance. Does that fit? All mouth and no trousers. Does that fit?"

Well, not really, no.