The first rule of Hacker News is that you don't talk about downvotes. But I'd like to educate you, so here goes. While I didn't personally vote you down, I can

The first rule of Hacker News is that you don't talk about downvotes. But I'd like to educate you, so here goes. While I didn't personally vote you down, I can absolutely make a guess why. You posted a URL (a Twitter one, no less) with absolutely zero context at all. You didn't say "Here's what [well known statistician] has to say about this study." You also pointed to the Tweet, rather than the article (or in this case, more specifically, the recent update to an already existing article) that the statistician Tweeted about. You left all the work up to the reader (two clicks and a bunch of reading before they know why you posted a nondescript URL). Why should anyone click on a URL to a Tweet without context? They shouldn't, which means that the URL adds no value to the conversation, which means the comment gets voted down.