Simon stumbles across the thread
Here's a description of the contestant's attempt. Someone's probably working on collecting some images to illustrate it.
Simon wanders around the edge of the haystack and almost immediately finds the thread attached to the needle, as it touches his bare leg. He is then able to follow the thread into the haystack and uncover the needle in just 3 minutes and 24 seconds, winning the task.
(Written by Karl Craven)