I would think a critical point here (though not necessarily the only point) would be the concept of lashon hara leto'elet -- something that's necessary to be said for a productive purpose.
Rabbi Yitzchak Breitowitz has a lecture on the subject where he asks if one can be an investigative journalist and stay within the laws of lashon hara. Well, what is the productive purpose? To reveal to the world that the latest celebrity got a DUI for the latest time doesn't really serve a productive purpose; on the other hand, to reveal that say, a mayor was taking bribes to give a major city contract to one company does very much serve a productive purpose. (There are also conditions that you keep the tone as neutral as possible, stick to what you know to be true, and that the outcome of the revelation will not be disproportionate to the offense. If this winds up with people recalling the mayor or their being charged in fair courts, that's proportionate. If this causes a lynch mob, it's not.)
Thus to say: "XYZ Corp has a spotty safety record, as proven from these documents, and therefore the city should not hire them for this project" should meet all these terms.