Seems to me that the delay between the brain activity and the conscious decision point could simply me measuring the subconscious. It's not inexplicable that some part of your brain that you aren't consciously aware of is what drives the decision to move your left or right arm. This doesn't really invalidate the concept of free will, it just suggests that your subconscious may be driving it.

More than intuitive , man has a need to survive. it is more than instinctive, it is innate. To survive he needs to be able to make agreements that are honest. He needs to have a moral standard that others understand and accept. If there are others within his circle of associates who accept these tenets then he is better able to make free will decisions. I don't think that the experiment involves activities which reflect real world situations, brain patterns aside. That's just me talking.