Imagine two scenarios:
1) I distrust Bob because he has betrayed me in the past. Bob tells me that "rojo" is the Spanish word for red. I don't trust Bob, so I go and look up "rojo" in a Spanish-English dictionary.
2) I trust Sue because on more than one occasion she came through for me when she said she would. She tells me that "Azul" is the Spanish word for blue. I am not confident in my Spanish, so I look it up in a Spanish-English dictionary.
Maybe the answer here is that the end of looking it up does not justify the reasoning behind getting the dictionary. However, I think it can be argued that if you really trusted Sue, you would not look it up.