I actually distrust such sources when I agree with them because I believe that I'm more vulnerable to being manipulated in that case. And I mistrust the proces

I actually distrust such sources when I agree with them because I believe that I'm more vulnerable to being manipulated in that case. And I mistrust the process of reporting anonymous sources like it, not Reuters per se. That is, I would mistrust this no matter who it is saying it because the process itself is untrustworthy and unverifiable. If I were writing such an article (and I have written quite a few news articles, mostly about scientific or legal matters), I would leave this information out entirely. A more trustworthy way to do this is to name a source and give their basis for claiming to know that. E.G. Person X heard Bengio say XYZ or what have you. But if your source isn't willing to go on the record, I would leave it out to avoid reporting rumors.