An unknown factor is if you even get to make a second try at getting 100% if you already passed with 50% on the first test. If it is possible to redo a passed test, I still find it unlikely that anyone would do so given that they know that they don't know the answers.
Including the edit that you're not told which one was right in the first attempt with a 50% score, it makes a lot more sense to accept the first 50% pass. Choosing different answers for the second try would only give the maximum score of 50% again, while choosing completely random answers again would only give the same chance as the first attempt, in which 0% is still more likely than 100%
Similarly, if you do get 100% on the first attempt, why'd you want to try again.. a lot of the answers here calculate the overall statistics when using both attempts regardless.
It had another run in the news following her death last summer.
There's nothing wrong with people TIL today, because she was right then and still is.