EdFred
Taxi to Parking
Remember that your goal is having the DPE, FAA, etc. credit your hours for your CPL.
A key question to answer is - regardless if this is within the rules - is the money you save worth the very real risk of having it blow up?
By that, I offer that there is a decent chance that - even if technically you're in the rules - that the DPE won't sign off / accept because we're in this gray area. What if the FAA comes after you as well as going after the other guy for cooking the books? What if you bend some metal, and the insurance company abandons coverage, and you're exposed? After a lot of money, time and pain, you may or may not prove you're within the rules.
IMHO, the juice isn't worth the squeeze.
Well, the thing is, how many DPE's are going to ask to see someone else's logbook if they see that you wrote down you were safety pilot, or that you put someone else's name in your logbook as safety pilot. Looking at just one logbook everything can look Kosher. If my logbook says 3.2 hours PIC XC but not listed solo, that's never going to trigger anything. And if your logbook says the same thing, that's not going to trigger anything either.
Now, it has happened, but only because both people were going to the same DPE at pretty much the same time with times that didn't add up. Both were logging PIC XC. But if I go to DPE Dick and you go to DPE Jane 6 months apart, this is never going to come up.
I don't know how often (if ever) the FAA has ever asked for someone else's logbook. I got a call from the FAA on a fatal crash from a former student, but it was a 5 minute (if that) conversation, and there was no request to see my logbook.