The time limit and your unfamiliarity with the statements ensure your assessment's accuracy by making it difficult to over-think your responses.
The Clifton StrengthsFinder works by challenging you to make choices between paired statements. Whenever your talents lead you to make a choice, we capture it. The combination of all the choices you made are used to calculate your top five themes.
If the time limit prevented you from making a choice, it is very likely that neither statement affected you in a way that allowed you to make a top-of-mind choice. Whether each of the two statements described you equally well, or neither statement described you well, your difficulty in making a choice reveals that the statement pair probably did not tap into one of your most dominant themes of talent.