It seems a bit odd that Dad flew out to help his 28 year old son drive back to PA. Dad flew to Spokane, sounds like he rented a car, and drove to Pullman to see his son. Then the two of them drove east. Dad must have dropped his rental car off in Pullman.
Basically a one-way airline ticket, then a hefty drop-off fee for the rental car.
I’m likely to believe as nutty as the son seems....dad is at the same level.