I calculated his striking distance as 1.5 feet, and I shot through a 70-200mm lens that had a minimum focus distance of about 1 meter. As long as he didn't move and I kept him in focus, there shouldn't be any sort of incident.
I met this small rattlesnake, about 2.5 to 3 feet long, on the side of a road in northern Nevada. He was very focused, but his actions were entirely defensive. He never struck, even as I picked him up with a hiking pole and moved him away from the road.