Are voices responsible for a bad script ?

No, unless they are authors. But in real life this is not that simple. When the voices get a poor translation full of mistakes and not understandable expressions, it is a professional obligation to let the client know about the issue. If that is possible, it is good to suggest an improvement of the text if this is really possible, but on many instances, clients can't decide or they just say to you: sorry this text was validated by the company so we have to stick to it. If no solution is on sight, you don't have other choice but to insist. In the case that the text can be corrected on the spot, then what we do at PrimeVoices is recording two versions, one as it should, and the other as it is. We submit both recordings to the client and warn him that further changes should be paid. In other cases, the text is fine but not convenient to do a voice-over, as it is too long or too short, or just written in a convoluted way. If matching the pictures is a must, as it happens with all videos, then we have to apply some editing skills. When we get texts in English and then we do other language versions, we insist that translations should respect the timings, but it is rare that the translator work with a screen in front and TC.