It should be noted that Dominican citizens and legal residents of the DR are not required to have a return ticket when flying from anywhere to the DR. If the airline asks for a return ticket (they will always do that if you have only one ticket and use any passport that isn't the Dominican one,, simply show your Dominican cédula and the questioning ends right there.
Leaving the DR you will be asked for a return ticket if you don't have a passport from the country you're flying to. Flying to the USA with a US passport moots that point, because similarly that any Dominican citizen can buy a one way ticket flying directly to the DR, a US citizen (or EU if flying to Spain/France/etc) can also buy a one way ticket to those countries and not be asked for the return ticket.
If a Dominican citizens loses his passport while abroad, he can go to the nearest Dominican consulate and ask for a carta de ruta. It's free of charge and with that offivisl form you can pass through Dominican immigration without a passport. If you don't have money to buy a one way ticket to the DR, the Dominican government will buy one for you at no cost to you ever, but I think they do that once in your lifetime. Technically, no Dominican can be "stuck" in another country since this option is available to all.
When Hurricane Maria hit Puerto Rico, a record number of Dominicans reached the DR by going to a Dominican consulate and asking for a carta de ruta. Many Dominicans going through economic hardship in other countries can return to the DR via that option too.
I hven't checked if other government offer this too, but I will not be sueprised if they do.
