Edmond O'Brien terribly miscast
First, the accent. Jesus. He's in Oceania (London) and was born there. Everyone -- Everyone -- else speaks with a British accent. But he's lumbering around with this taxi-driver, imfromnewyorkfuggetaboutit accent. He's ridiculous.
Then, the chemistry. There is no chemistry. This guy isn't a leading man. He is a pack animal of an actor. In "D. O. A." he's superb. In this movie, he's absurd.
I mean, it's still a good movie. I'd watch it just for the Donald Pleasance cameos, but Jesus.