Consider the train problem:
A train is barreling down the tracks. At a fork, you have the option of flipping the train to the left branch or the right branch. On the left side is someone you know, tied to the rails. On the right, there are five strangers.
Which way do you throw the switch?
A philosophy professor posed the question to his two-year old.
The great thing about this is that he was still solving a problem...it just wasn't the expected problem.
I think a lot of frustration can come up in a classroom comes from ambiguity. I may have a problem and anticipated solution, but if that isn't clear to students, conflict can pop up when they take a different path. Even more, defining specific solutions to problems worth discussion is a poor teaching method.
Next time you're given an unexpected solution, consider the validity of a different point of view.