The judges honestly didn't know what they were doing. A team was starting motors and using electricity after their sand timer started;
So what should be done in such situations? By doing nothing, you perpetuate the problem.
Often, the first impulse is to file a protest against the team whose device was judged improperly. This is often taken to be an accusation of cheating and some tournaments automatically dismiss such appeals.
A better (less used) action might be to appeal that the judges failed to judge the devices properly. Results from these appeals are more likely to address the real problem and provide a wider reaching remedy.
Situations like the one mentioned can be difficult to appeal. The judge was (presumably) in a much better position than you to see how the device operated and made a decision. Once a decision is made by the judges, it is correct by definition (That's their job). The onus is on you to present valid evidence to the contrary.
Some tournaments accept appeals only about a team's own device, not about other devices. A possible way around this is to appeal that your device was not judged with the same standards as others.
Before filing an appeal, make sure you have good solid evidence to support your claim. Something you saw from across the gym or overheard from people talking in the hallway won't carry much weight.
Appeals are always a difficult situation. Everybody thinks they're right and the implication is that someone was "cheating". Judges decisions may sometimes be colored by preconceived opinions or associations, but cases of intentionally biased decisions (in my opinion) are extremely rare.