My guess is because venison has no fat if you cooked it as long as pork you'd be able to pick your teeth with the fibers. Com'on Kevin you should know that livin in dodge the deerville. Don't you hunt'em?
Also, why don't you get some thick cut peppered bacon and lay over the top of the roast whilst it's cookin?
ModelMaker
Kevin are you going to cook at Mason City? We are going to camp across the river from the event. Probably Thur. night or Fri. morn.