This is the "Gadson" Flag, not the "Navy Jack" Flag, which had a red and white striped background with an uncoiled snake across it, with these same words, "Don't tread on me". This Gadsen is in fact the later version, known as the "Jack" Flag. Your Presenter owns one with red and dark blue stripes, yet not exactly like the Jack flag, but with the same uncoiled snake and same verbiage.

Compare: http://www.gadsden.info/snake.html; http://www.history.navy.mil/faqs/faq122-1.htm