To be honest, since this is a trainer type plane the flight may not be effected that badly, depending on the severity of the twist. The plane may roll one direction faster than the other and you will definitely need to adjust the aileron position slightly too. If not bent too badly I doubt it will cause a crash but once again have an experienced pilot fly and trim it before you try to. Be sure you point out the defect so he will know what MIGHT happen.

Again - how much twist does it have???

Naturally the best solution is to fix it BUT that may not be needed