What is ironic about the location Pablo gives the Falangists as to Ramon's whereabouts in the story, The Wall?

Pablo chooses not to expose Ramon's hiding place, hoping to make fools of the officers by giving them a random location and sending them on a wild goose chase. Ironically, however, it turns out that Pablo's "joke" causes Ramon's death, for Ramon ends up at that location by chance. Thus, Pablo's life is spared but he now bears the responsibility for a friend's death.