We don't KNOW that he had a one-way ticket (Do we?).
We speculated that he did because of the "He was going to go to stay in the Bahamas and go to school" story that we think Howard concocted to cover that.
My son traveled the world for several years. These were maybe two month trips...but he was in Japan for a year. All his tickets were one way.
"We don't KNOW that he had a one-way ticket (Do we?)."
No, it was speculation in trying to find a way to make the story HKS told make sense.