When the time traveler explains the accelerator bracelet to Mr. Judson, she says, "when this switch is on...", and proceeds to accidentally switch it on.
In the final scene, the second hand of the clock behind Henry doesn't move, even when the bracelet isn't activated.
At the end of the episode, Henry thinks to himself that he will never be able to speak to another person again. This is untrue, since, based on what the lady told him, he should be able to get close to another person and that person should be affected by the bracelet's power.
The time traveler tells Henry that the bracelet will affect anyone within 5 feet, however Henry comes within 5 feet of several people and nothing happens.