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.