Ellítt Blake had Columbo at the guillotine with his head in the line so to speak. He DID try to kill him although Columbo took a huge gamble in switching up the collar That took cajones. I mean losing a finger is one thing but a whole head? Anyways he outsmarted Blake in the end anyways

Ahh, yes, forgot about that one.

Swan Song. Tommy could have easily taken out Columbo up on that hillside all alone in the dark. He even asks Columbo if he's afraid of being alone with a cold blooded killer.