From the book Comey says he said
The first part of your response was fine, not the second. We are killers the way they are.
In the book, Comey describes the scene as Trunop just ranting about it, and finally Comey couldn't take it when Trump said
"I gave a good answer....a great answer....that was a great answer right"? And Comey just told him. He said the whole scene changed in that instant, and the meeting was over.