Adding to my speculation of the Frats -misplacing- their passports and only their passports... they were moneyless already and we donīt know if they were getting money for the next leg:
On E09 there's a confessional, taped in Portland, where they state: "I was not a fan of buying the shoes".
Why so many explanations if they were not the "mistake experts"? Why if they were with the pack? Why if they were the winners? God forbid. Why in Portland? Why that late?
Here is my speculation:
During leg 10 the Frats misplace/forget/abandon their documents, as they are not worried for the money since there is none or little. Then, after the speedbump, they arrive last, way behind as they had been back somewhere to pick up their documents after they figured out they didn't have them, they get eliminated, then they, again, go back looking for their passports, find them or realize where did they leave them, but the place (where they left them) won't open until next morning.
They were so late to the pitstop that our Moscow informant missed them and second place went to Toni and Dallas.
F3 depart Moscow at 7AM on next day to Portalnd, Frats are not in the F3 but attention is at how will they get out of Russia to join the rest at the finish line since they don't have their documents.
After or during the final episode (E11) BVM has to let us know if any left-behinds arrive safely back in the US and that's why they are taped late in the evening at the Mansion, so we all get to know they came back safely and all of the explanations on how they lost their documents and how they had to take the Amsterdam-Seattle connection.
They might have been sent as decoys in the evening -just for confusing US on WHO had lost their documents-!