Flight instructors may log any flight time as PIC whenever they are providing flight instruction, whether or not they are acting as PIC (FAR 61.51). This mainly applies to FAR Part 91 operations! An instructor may not give flight instruction during a FAR 135 or 121 operation unless he/she is a designated flight instructor as stated in the carrier's approved operations manual.
So, Ewald, as an FAA CFI could legally log PIC time under the FAR's even if not the nominated PIC as long as he was instructing. Interesting...
Wasn't there an FAA rule saying an ATP could log any flight time in an aircraft they were qualified in at one point, even if not the handling pilot? Maybe that was a possibility?
https://www.aopa.org/training-and-sa...mmand-pic-time