My shop is a great place. I've known the owners for 20+ years. The Nissan dealer diagnosed a bad wheel hub and they told my wife the transfer case was leaking a little. If they had (according to my garage) lifted the Pathfinder they'd have seen the loose wheel. For them to diagnose a leaky transfer case without looking underneath is shady. The transfer case had such a small amount of oil coming out of it that it is not something to worry about.The question I have is, was it the loose lug nuts the whole time? It's been some time since you had the CVT replaced, correct? Did the Nissan dealer charge you a diagnostic fee? Given the history you've had with them, they may have just taken it for a quick drive, heard the noise, guessed it was a bad hub and parked it. If you paid them a diagnostic fee, I'd be pissed that they didn't catch loose lug nuts, or maybe they pulled a wheel and forgot to tighten them.
To me, your shop that said we'll tell you what the problem is for $50 is shady as hell for going about their business that way.
Had a similar experience with my FIL's Maxima some years ago. He had just had it in a tire shop and shortly after it "started making noise". He called me asking If I'd follow him to the Nissan dealer because he was sure it was a wheel bearing. I ask my FIL, are you sure the lug nuts are tight? He laughed at me.. Yeah they're good. It was just in the shop! As I was following him to the dealer, the front left wheel left the vehicle and stuffed itself up into the fender, doing body damage. I had to go home to get one of my low floor jacks, remove one lug from the remaining 3 wheels to use in place of the missing lugs to get him to the dealer.
I guess my point is, any type of weird noise after a shop visit, make sure all your lug nuts are tight. **** happens.