I wouldn't be surprised that a native speaker would do something one way, and a test would insist the 'correct' way is actually pretty awkward and wouldn't be used.
This... In Vietnam seeing some (as a 30yr old native English speaker) of the "correct" answers to VN made English homework or tests is interesting to say the least. The questions are so awkward, pretty sure the only reason the students able to deduce the answer is because they have been taught vn-English so it makes sense to them ;)