I think you have the ordering wrong. If someone defecated on my dinner table I would never eat off that table again. He might as well have set fire to it. And since the table is worth more than the iPad, I think the first scenario is actually the worst.
It seems like a small thing, but it does highlight how something like theft is easy to judge the seriousness of; namely, stealing a $2 candy bar isn't as bad as stealing a $20 shirt, which isn't as bad as stealing a $20,000 car. But sometimes it can be difficult to judge the damage of vandalism, and the vandal almost always thinks it is a smaller deal than the vandalized. So let's say someone is going to slash somebody's tire. The vandal might think that it is no big deal, like a $50 tire that needs to be replaced. But the vandalized is thinking "I'm going to be late to work to deal with this, so I'm losing pay, and I have to make sure that the tire salesman gives me a good price on an equivalent tire, etc etc"
Having said all that, it certainly seems like calling the police for this particular incident of vandalism is way overkill, but (playing devil's advocate a little), what if the administration is totally technologically ignorant, and think that this kind of situation requires a $300/hour consultant to come in and "clean" the "infected" machine? Stupid people have all types of higher costs, and if you make them incur those costs, they will blame you, not themselves.