Maybe they thought they'd swim to Russia?
On a more serious note, I was also surprised they got that far but still doubled back.
Honestly, I never thought these guys were geniuses, but the stuff that was revealed today about their efforts to disguise the vehicle and flee by boat is literally some of the dumbest reasoning I've ever seen from suspects in 20 years of following true crime. I think I put more thought in the past two months into trying to figure out what they were thinking than they ever did at any point.