Sarah catches fire
Here's a description of the contestant's attempt. Someone's probably working on collecting some images to illustrate it.
Sarah's first instinct is to try to catch an infectious disease from someone. She then goes with a similarly lateral idea by being shown 'catching fire' - apparently holding flames in both of her outstretched hands, and then 'blowing' them both out with her breath. However, Alex can be seen in the footage, running around in the background with a fire extinguisher, to put out the flames, which Sarah had assumed would be edited out. Greg awards her third place, blaming Alex for ruining the magic of the video.
(Written by Karl Craven)