Loose is fast! 
Too loose, is slow also.
I have never driven that track but even in a relatively straight line you seam to be fighting the wheel. Again, I am not an authority as I have never driven the track. I have friends who have excessive hand movements, in my view. Its part style. i am ready to catch the car if need be and in some corners I turn in aggressively to get the car to rotate but those moves are trying to unload the car and rotate.
I have learned the hard way that SCCA and NASA have different rules regarding what is fair play. In NASA once you get your front tire to the other drivers door, its your line and your apex the car being overtaken has to give way even if it means two in the grass or going off line.
SCCA is a little different you have to give racing room, and you have to keep off of your competitor. you would need to see the view from both cars to make a determination on that. In general my view is that the person making the pass must do so without contact. I will add that the person being passed should not block. I really cannot say from the vid that the BMW was putting a block move there but i really do not know.
As Kyle said, right or wrong when you have contact that is going to slow you down or put you out.
over the years my attitude is that i would rather live to fight another day, or in racing wait till i get a better run on them.