I put physical in quotations for this very reason. I couldn't give you further explanation of his motives, because... well I am not him. But the way he explained it to me was he felt there was a connection between two via flesh contact. This connection was different in weapons training, and just didn't float his boat.
As far as the heightened sense of danger is concerned, there was many a time were we attacked and defused attack with the tanto. I enjoy that alot and wish my new dojo would pick up the habbit