Perhaps SP is not being entirely truthful.. or embellishing.
Well you'll need to point to a specific example of him embellishing before I'm convicting the guy of embellishing. Furthermore, you'll need to explain how he survived and supported a family with no income for 2 1/2 years--there is no disputing this fact. Finally, you'll need to explain how he could afford to travel all over the world for the next 25 years essentially working part time.
Has it occurred to you that perhaps SP was Cooper?
Many travel and support themselves through legal or illegal means, just because you don't know how he supported himself doesn't make him Cooper. Lots of those guys became drug dealers...
You should assume he is untruthful... be skeptical to be a critical thinker.
As for SP being Cooper, IMO, the case is very weak circumstantial and similar could be applied to tens of thousands of people..
Is it possible, sure. but to be honest, I have been focussed on researching Hahneman, a much much better suspect. (based on info I have)