I have a difficult time with a video such as this. It is obvious they were in a holding tank or pool of some sort so these are not bass in a natural setting with food source, competition, etc.
Second, a large majority of the bites should easily be detected by a knowledgable, experienced angler.
Third, I'm guessing the film is dated. Whether people like it or not, bass fishing is moving to a different game. Instead of using hi-stretch monofilament only a handful of years ago, we are now fishing no-stretch flouros and very sensative braids in which an angler can pick out every blade of grass a bait may touch.
Another situation is a strike vs a bite. There is much disagreement about a reaction strike vs a feeding strike/bite. Who knows what/when the truth is, but some of the hits in the video appear that the bass have no intention of eating the bait. Don't get me wrong, reaction strikes are very effective, completely legal, and if you're not benefiting from them you are not getting the most out of bass fishing.
I've never been a big fan of the free fall method on some of the spinnerbait / buzz tactics.
Everyone has their own opinion though. I've never been able to research my own experiences underwater, but I'd imagine a majority of those bites would be easily detected.