Kristoffer spots two key loopholes

Here's a description of the contestant's attempt. Someone's probably working on collecting some images to illustrate it.

Kristoffer saves himself a lot of hassle by moving the tea cart to where the balloons and cacti are, so he doesn't have to keep running back and forth. He also spots that the task says nothing about the balloons having to remain inflated, so bursts them and lays them across the cacti, saving himself a lot of space. In total, he manages to fit 16 cactus-balloon pairs on the cart before time runs out, winning the task.

(Written by Karl Craven)