Why does the wrong source data item have the discrepancy?

When a data item like a derived BMI has more than one source data item, the validation check must designate a single column as the one against which to create the discrepancy, even if it is impossible to know in advance which one is faulty. A BMI that is out of range might be due to a bad value for height, weight, or unit, but one of them must be preselected. However, all relevant values can be displayed.

See also Why is a query on a different item in InForm than in DMW?.