From the FAA Private Pilot PTS (Practical Test Standards);
Applicant's Use of Checklists
Throughout the practical test, the applicant is evaluated on the use of
an appropriate checklist. Proper use is dependent on the specific TASK
being evaluated. The situation may be such that the use of the
checklist, while accomplishing elements of an Objective, would be
either unsafe or impractical, especially in a single-pilot operation. In this
case, a review of the checklist after the elements have been
accomplished, would be appropriate. Division of attention and proper
visual scanning should be considered when using a checklist.
So the "official" word is that it's a check list and not a do-list.
Your brother is an Engineer, that explains a lot, no pun intended.