And getting students to think about why something might happen before they are told is a very common tactic.
Also, extending a theory is also very common, where they are told something one day, and why it doesn't always work in all situations the next.
I am sure the teacher would love it if everytime she tried to explain something, a student came up with a smart ass answer about how she could have tricked them.
"So why does this cloth pick up the bits of paper?" "Cause you put glue on them" hahahahaha
That is going to be a great class from that point on.
For example, in a science class students are typically presented with a phenomenon, asked to speculate about it, and then presented with a scientific explanation. Do this often enough and a clear pattern emerges - phenomenon -> scientific explanation.
In the case of the article, it was actually phenomenon -> human interference, but it shouldn't be surprising that the students assumed it would fit the usual pattern.