Most used car dealerships won't know about the issues the Pathfinder has unless they have had an issue with one in the past. When checking out the vehicle to sell....most dealers check for mechanical issues that are safety related and or prevent it from selling. They will probably change the oil but almost no used car dealership does other maintenance or fluid changing.....especially on something that has over 100,000 miles. I bet his 107K mile pathfinder still has original spark plugs in it too. It is not entirely the fault of the used car dealership nor is it the fault of the buyer........it just plain sucks for both parties.
I worked at a new Nissan dealership for 17 years and personally know that unless the vehicle was low miles and they Certified it with Nissan.....they did not change spark plugs or do any other fluid checks/changes other than oil.
I now own a small used car dealership and specialize in Nissans....however I won't buy an Xterra or Pathfinder with more than 80,000 miles on it. I always check them check out for all of these issues. I actually have had 2 of them get brand new radiators and new transmissions....free under the 80K radiator warranty- from Nissan.
That would be the biggest tip I can offer someone buying ....Buy with less than 80,000 mile or make sure that the bypass and or new transmission has already been done.

Kind funny, I just read today in consumer reports the section of used vehicles to stay away from and the 05-06 Nissan pathfinder was one of them. I did the bypass, but still think I'm going to get rid of it.