If only the scores I also doubt that it's rigged, it has to be on how they play and if there are intentional misses you have to show us the actual games for us to see if the teams are rigging the game, FIBA judges and officials will not let rigging to happen because the teams are not corporations or state-based but these are countries fighting for pride, no country will send a team to take part in rigging a game, they will lose pride as a nation, it can happen in leagues but unlikely in international tournaments.
We will need to see the actual game to see if there was something suspicious at the time that could have influenced the results one way or another, and if there is no evidence of this then we have no authority to say that the matches were rigged.