They were in the defense. The goalie wasn't good. He maybe saved few chances, some of them because of the Nigerians clumsiness (or maybe because they were underestimating Tahiti and wanted to go inside the net with the ball). The goalie conceded a goal by his mistake and made one more terrible mistake when one ball was thrown near the corner. So he wasn't good against Nigeria. Even the commentators here were talking how his inexperience for such an event made him tremble.
Plus, Tahiti has played better before against Australia, New Caledonia, Solomon Islands and New Zealand.
Though, I agree that they went for the attack, unlike Andorra (which is the worst team ever with their game play). And I was hoping that Tahiti will score 1 more goal, as they had a great chance with a header. I do applaud them for the team spirit and their goal celebration, especially since most of them are working in hotels are accountants and what not.