So said some prewar Mashgiach.
Sometimes, sure. They say unclear numbers, etc. hint at dishonesty. Presumably, this doesn’t include writing for the drawer.
But what about doctors? And, well, Talmidei Chachamim (like the Mussar/Torah clashes on “Negios”, etc., see Emuna Ubitachon Chazon Ish chapters 3, 4)?
It could be Dysgraphia, poor motor skills, personality, etc.