It sounds like there a bunch of experienced travelers on this thread, so I will pose a related question:
Say a traveler has a one-way ticket on Airline 1 to Country A. When checking in for this flight, the agent asks for proof of onward travel. The passenger presents a printout showing either an airline ticket on Airline 2 departing Country A , or a cruise departing from Country A.
Does anyone believe there is concern with this scenario?