Why cops are so strict during govt exams?

For example, they check the ID card and the hall ticket thrice. Even if you are a minute late, they will not let you in, and they will not let you in even if you bribe them (maybe not all but most cases). I am aware that cops and staff are afraid of inspection officers, cameras, and other things, but these exsist even in all government offices. So what is unique about government officials giving their all at the polling station and during exams? The reason for my curiosity is that the government can utilize these two situations as a case study to apply them in all government offices in order to achieve maximum productivity.