logging (PIC) time

any opinion rendered from his office that interprets the FARs is
binding on the FAA. That's as "legal" as it gets, since the FAA
enforces the FARs.

The regulation itself and any court rulings take precedence over the
Chief Counsel's opinion.

And the Chief Counsel's opinion was erroneous. Section 61.51
describes the conditions under which a pilot can log PIC, and acting
as PIC is only sufficient under two circumstances, 1) acting as a
safety pilot, or 2) the pilot is an ATP when an ATP is required.

None of the Letters I have contradict the interp that Rick Cremer
provided, but none of them support it, either. Quite a number of them
describe the conditions under which a pilot may log PIC, and merely
acting as PIC isn't one of them.