Just about every security software that I've ran has thrown out a few false positives. It's when it happens often that there's a problem & the software is buggy or may be misconfigured. For example, there's "Paranoid" option in Emsisoft Anti Malware settings (all in one AV/AM app) & "Aggressive" on Bitdefender Total Security 2014, there are warnings with both that more false positives should be expected if these modes are activated. So it's not the software all of the time. However never reduce settings to the minimum possible to avoid false positives, real threats may slide in.
Though I've ran ESET NOD32 for years & really like & recommend the choice of security, it always throws a false positive when the NoScript home page (Firefox security extension) opens after being updated. I've reported this issue several times, with no solutions, to the point that I've just learned to live with it. All it is, is a popup & a block on a portion of the page. None of my other security choices, nor MBAM Premium, which is excellent for this, blocks the page from opening. Of course I could white list the page, but I don't like to do that, as content on a page can change at anytime. And it's not like NoScript updates daily, maybe once a week or two.
There is a delicate balance in detecting real threats while at the same time keeping false positives to a minimum. To be honest, I can live with one every now & then. At least I know that the software is acting in real time. Also, there's many times when downloading otherwise honest software, that all of one's active protection will throw the red flag. CoreTemp being a great example. Only one site that I grabbed it from & I forget 100% which one, may have been Major Geeks, that finally allowed it. The reason it's flagged is the 3-4 options of bundled adware that comes along for the ride. That's not a false positive, the security is doing it's job, protecting against PUP's.