I thought you were familiar with the multi case I mentioned. It's been cited in a few posts here and there. Here it is:
http://www.ntsb.gov/legal/O_n_O/docs/AVIATION/4008.PDF
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The falsification charges resulted from the examination of both respondents' logbooks by FAA aviation inspector Donald Bennett during the investigation of an accident that occurred on 10 April 1992 involving respondents' Piper Apache aircraft. The inspector testified that
the two logbooks were mirror-images of each other for over 200 flights. Both respondents were listed as pilot-in-command (PIC) for these flights and it was unclear when, whether, and what type of flight instruction was given.
Respondents testified that they were co-owners of the aircraft, N3494P, and always flew the aircraft together, splitting the time 50/50, in an effort to build PIC time. They also flew together and logged identical time in a Mooney M20E, N6933U.
They asserted that the act of logging identical PIC time on each flight was permissible since when one was operating the controls of the aircraft, the other was instructing.
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The NTSB report of the accident is here:
http://dms.ntsb.gov/aviation/AccidentReports/wqemvfjqv3oeuo3upyfjco551/O01282013120000.pdf
You can see why I referred to "extreme circumstances." I've always wondered what the back-story was., even with the ice encounter. Maybe there was a really bad attitude by the one (or both?) after the accident. Maybe they had different stories about which one was playing "instructor" on this flight.
There's a lot of logbook issues that the FAA is not likely to be concerned about - unless something happens to make the FAA take notice. In which case, all bets are off and, depending on what happened and the pilots' attitude toward it, the FAA might choose to take the revocation path - which is the standard penalty for logbook falsification (and what happened to both of those CFIs).