Looking at the picture, while that's definitely small for a 2 year old, it also doesn't look too thin. Were they really only feeding it one fuzzy a week? I would even go as far as to say it should be on large adult mice, almost large enough for weanling rats, rather than just small adult mice.
Are you 100% sure it's a 2 year old? And it was fuzzy mice? Just seems strange, a snake that's the size and shape of the one in your hand looks like a decent 4 - 6 month old at average weight, not an underfed 2 year old. The back half of the tail on your hand doesn't look emaciated at all, and that's often where the snake looks the skinniest first. A ball python that's only been eating fuzzies for two years would look almost skeletal.
-Jen