Yes, Jigsaw killed people. He once claimed that never never killed anyone, but this is true in only the most technical of definitions. John Kramer never murdered anyone directly with his own hands, but he definitely killed people. Even in the first Saw movie, he killed people. This is one of the things that makes Jigsaw such a compelling villain. He truly appears to believe what he is saying, but his actions don't always match up with his words in any reasonable way. Jigsaw said that his test subjects always have a choice. This is not always true. For example, in Amanda's first test, the Reverse Bear Trap, the key to release her was planted inside the guts of a man lying sedated and immobile in the room. Amanda had to cut the man's stomach open to get the key. The man was killed, and he had no choice in the matter. These kinds of traps, where at least one person has to die regardless of what choices are made, became more common later in the series.