It could be enough if the nozzle just stops moving while touching the model being printed - based on the type of material, it might start burning.

And if you want to be outright malicious, you can disable maximum temperature control and do the same with much hotter nozzle rammed into the model - and even print an extra burnable model when you are at it!

Or count on the power supply or the wiring catching fire instead due to overload.