It's unusual that a Peace Corps volunteer would want to meet with Marines for any reason other than medical, but I would be willing to bet that someone from the Marine Corps would want to corroborate their story with people who worked in other government (sponsored) positions. The ineffectiveness of the drug (Mefloquine/Lariam) in their case, and the psychotropic side effects on the other hand for the majority of people who experience any problems with the drug.