Translator is an ethical profession
Translator is an ethical profession. As such, it requires conscience not to cheat even in little, because very few will be able to verify, even if they know the language of the original (sometimes we need  to read works of translation knowing the original language, yet do not want to verify them line by line).
Misplaced words, altered style, contorted emotion, biased attitude, wrong mood, let alone clear obfuscation of the original meaning—all of these should be subjects of a mindful translator, who is to be trusted.
 For example, when we teach someone who does not have access to the original text. In this situation, we rely on the translation. Situations may become even more intricate: Nassim Taleb, for instance, admits in one of his books that he himself, being a native speaker of Arabic, read some of the non-Arabic works of orientalists on Al-Ghazali and the end of philosophy in the Arabic world, accepting their arguments that originated from the illiteracy in Arabic.