This seemed to be unusual by my recollection. It was not technically needed given his many thousands of hours, and I certainly did not need it as PIC time specifically as well. He had a need/desire to actually log PIC time in my PA28-181 to go along with his multiple PIC hours in his C425. After thinking about it after, I speculated that his doing do so could have been necessary as the flight was actually filed IFR while I was in the second 6 month period after my last IPC and not technically able to file, or that it enabled him to establish currency in my plane( as his was almost all turbine time of late), should he do a pinch hitter for my wife. It was not important enough for me to ask as I got my endorsement and the price was right.