Sure it does. The UN Navy does not have assets trained to deal with hostage negotiation. That is a the job of a federal law enforcement agency. If not the FBI, then it would likely fall to NCIS.
Of course there were still 18 other pirates holding the missionaries hostage.
If the objective was to free the hostages, and not just punish the pirates, I think the book says you have to tease the pirates along a little bit longer ~ maybe even invite them to dinner with the captain ~ whatever it takes to separate the pirates from the hostages.
Once you've got them separated then you turn on the pirates and kill them all.