There may be several reasons why a tall expert is small:
1. Genetic factors: The size of hands is greatly influenced by genetic factors, and even tall individuals may have relatively smaller hands due to genetics.
2. Individual differences in growth and development: Everyone's growth and development situation is different, and although there is a certain relationship between hand size and height, it is not absolute.
3. Malnutrition: Nutritional status may also affect hand size, and if malnourished, it may lead to insufficient hand development.
The above are just some possible reasons, and the specific situation may vary due to individual differences. If you have any questions or concerns about this, it is recommended to consult a professional doctor or expert in the relevant field.