I'm not trying to take the side of these folks, but... even so, I would not think it would contaminate said device unless people touch the device again after cleaning themselves but before washing their hands. If that's the case, that is quite disgusting.
When you go #1 or #2, microscopic particles of the two are released into the air - that's why you can smell it. You're able to smell things because microscopic particles of said object are going inside your nose. That's how human feces get onto your phone. People are sitting on the toilet, playing their favorite iOS/Android game or texting (for example).