VIDEOS:
Students with lightsabers
In the first episode, Master Mudmud emphasizes how dangerous lightsabers can be, with poorly-built lightsabers capable of exploding. In the second episode, Randy shows off his own personally made "rush-job" lightsaber, which of course explodes and eviscerates him on the spot.
Example of:
Forbidden Chekhov's Gun
Example of:
Weakened by the Light