As we state in the answer:
According to Oracle documentation, the state of a variable that you SELECT INTO will be undefined if the statement raises TOO_MANY_ROWS....In practice, however, it seems that the data from the first row returned by the query is assigned to the variable(s) in the INTO clause; only when the second row is fetched is the TOO_MANY_ROWS exception raised.
We have had several quizzes that delve into such "indeterminate" behavior and generally have taken the position that if the actual, day-to-day experience does not seem to be indeterminate (in this case, the variable(s) are populated with the data from the first row fetched), then it is a legitimate topic and answer for a quiz.
Several players raised objections (of course!). One person objected to making a quiz involving undocumented behavior like this an "only one choice correct" quiz. That is too harsh a penalty for getting it "wrong" (which in this case would mean following what the documentation says). I agree with this. We are definitely going to change the question type to "more than one choice might be correct" and rescore. But we will likely also correct the scoring on some of the other choices.
Before I do that, though, I invite players who submitted concerns and code examples to post them on this blog. They've made some very interesting discoveries!