I was about to post about the same suspicion about this app. I don't think this Flixgrab app is downloading the untouched netflix video. It could be doing some sort of background screen capture and re-encoding on the fly or some kind of download and re-encode of some sort.
Plus, the mediainfo that @TheOneWhoSees posted is not how an untouched netflix download normally would look like.
The easiest way to really find out is by using Flixgrab to download something that was previously released that we know is a legit netflix download. There are plenty around here. Compare by filesize, mediainfo, screenshots, number of frames. It'll probably be different and if so, then this Flixgrab is not giving untouched video.