Question: How to stop and infinite regression
When you are pulling the string to get to the truth, the path of "how do you know?" won't get you there.
What you will be looking for is an outpoint of data, frequently an omission, or altered importance, or misassociation to determine the area
of the problem. From there you can find the who, and make things go right via that corrected person, or his senior, or his replacement. ...