The Case of the Attempted Murder

     "NAME_1's account of the attempted strangling of Mrs. NAME_2 is pretty farfetched," Inspector NAME_3 told NAME_4. "Yet he passed a lie detector test. NAME_5 drives a delivery truck for Best Cleaners," explained the inspector. "At five minutes before noon Tuesday he drove to the NAME_2 House and stopped the truck in the driveway. He spent about two minutes filling out his delivery reports for the morning. Then he got out with a dress and two suits.
     "As he closed the cab door, he noticed his front wheels were parked on the garden hose which ran from an outlet by the garage around to the back of the house. NAME_5 claims he got back into the truck and drove forward a few feet so that his engine was in the NAME_2's empty garage. 
     "Here he noticed the door between the kitchen and the garage was open. He saw Mrs. NAME_2 lying on the floor by the stove. He rushed to her, he says and was trying to revive her when Mr. NAME_2 came through the door of the garage. NAME_2 had taken the day off to water his backyard garden. He had been hosing down his flowerbeds and hedges for half an hour when he noticed the truck in his garage. He walked over to investigate.
     "We can't get NAME_2," Concluded the inspector, "To state definitely wheter he thinks NAME_5 was trying to throttle his wife or revive her."
     "No wonder the lie detector test didn't trap NAME_5!" said NAME_6.

Why not?