This sounds like poor consideration for edge cases - not really a problem with the UI or people clicking through it too fast. Anything that could be interpreted as remotely fatal should've shut the machine down.
You also have a hardware lock on the power - this can be as simple as a hardware timer (a RC circuit siffices) which limits how long the emitter can be on within in a given window to be safe.
Never trust the software. If you must trust some software, create a minimal set you CAN trust which isolates the rest of the software from the hardware.
You are correct, the discussion about how to exercise this bug (fast UI, blah blah) is interesting to hear but totally irrelevant to the lesson (don't trust software).