About the same time you were posting this Dershowitz was on MSNBC being grilled about this very thing as the host tried to make the same negative insinuation as you. I missed part of his response because I was frying bacon at the time but he seemed to come away unscathed, to the obvious disappointment of Ms Hallie Jackson.
I'm sure a video clip of that exchange will soon be available somewhere, you might enjoy seeing it.....or not.