Yeah, I was under the impression that he leaked information on the slaughter of civilians in the Middle East by soldiers/mercenaries. My familiarity is clearly cursory.
Along with a ton of other stuff that wasn't germane to that incident. Manning's big issue was that they released a bunch of classified material without much regard for what it said. It was very broad in scope. Had it been a narrow subset of the data, Manning would have had a better chance of being considered a whistleblower.