You need to check your sources for this information. If I remember correctly, that snake was actually just over 7 ft in length. World record edb was just over 8 ft and weighed around 36 lb(world record for venomous snake weight). There are many pictures of diamondbacks online with overexaggerated sizes. The trick is to get someone to stand a good distance from the snake and take the picture so that it looks taller than the actual person.

Justin