You have to hold down the space bar or L key to fire. Simply pressing it won't do a thing. But if you hold it too long you'll fire two or more. A single press should fire a single shot, so I consider this broken.
Also may as well not even have the screenshots thing if you're just going to discriminate like that. You do know it's easy enough to hide things on Windows too right? Or to make a mock-up screenshot on any operating system using pretty much any paint type program? I mean pretty much any online achievements are going to be highly dependent on the honor system anyway because everyone's machines are going to be different and there's no real way to verify anything for 100% certain. All this does is show and prove that you have personal biases because you personally use Windows. It's the online equivalent of a "Now Hiring" sign with "Irish need not apply" underneath.