@AHDinh -
You are interpreting that information correctly. I tried 2 things yesterday with a quiz and a student account. I tried one where I started the quiz and closed the browser. Another test I started a quiz and just left the browser open. In both cases the answers I had selected were marked answer and the quiz auto submitted at the until time.(no extra time). I did not try something where the student was still active in the quiz, but my guess is that it would have been auto submitted at the end time as well.
With what you posted, something does not seem correct - the last line of submission for several problems is what I would expect for several questions being answered and then the quiz being submitted finally.
The good news (mostly) is that the student did not get more than the allotted 2 hours.
By the way my test above was with classic quizzes(which is what I use). What quiz type were you using? Classic or New?
Ron