To what extent is the attribution of the saying, "If you see me straying from the path, then take me by the collar and shake me violently, and say to me: 'Fear Allah, O 'Umar, for you will surely die,'" to 'Umar ibn 'Abd al-'Aziz accurate?

The phrase "May God have mercy on a person who points out our flaws to us" is not found in the available references. However, it was narrated that Umar ibn Abd al-Aziz said: "If you see me deviate from the truth, put your hand on my collar, then shake me, then say: 'O Umar, what are you doing?'"