On the contrary! it is your duty and responsibility, as a team member, to check your colleagues work and the code quality. Otherwise you are not only a bad team player, you are also unprofessional as a developer. Just a solo code typist.
Of course, It would be easier to avoid confrontation, do your s*it and home like parent does. Just easier, not right.
His code is the team code and therefore your code as well. Code reviews are to critique code, not to criticize team mates, however, if you cannot even make a remark like 'Do WE see how much better...' you have a bigger problem than just bad code, you have a rotten team, and if you STFU, you are only making it worse.
For the sake of your project, your company (and then your job), you must do all you can to shed light on these team issues. Talk with other team mates, learn how to organize a team retrospective, ask for help on this matter. Care.
And specially, don't count on managers to solve these issues by themselves, they can help, but they are not your babysitters.