I'm confused: the correct answer is the row that is returned "most of the time"?
If yes, then it isn't a good question, as other answers might be possible. If you can receive other rows with TOP 1, then you should have added an 'It depends' answer.
For the rest: nice question :-) (also good layout and structure of code)
I agree with you: no "order by", no default sequence.
But what does this mean?
Always use the top with an ORDER BY clause!
Syntax should be appropriate to the hints.