Error: When validating relationship rules, invalid cardinality is not detected
When validating objects in ArcMap, using the Validate Selection command, or when using IValidation::Validate, some objects that break relationship cardinality rules are not returned as being invalid.
Cardinality rules on composite relationships are not being evaluated by the system. Cardinality rules on simple relationships are evaluated correctly.
Solution or Workaround
The workaround for this problem is to create a class extension that implements IObjectClassValidation. In the IObjectClassValidation_ValidateRow method, you can write code to manually validate the relationship rules cardinality.
For an example of how to implement a custom rule, see the developer samples:
Samples\Geodatabase\Class Extensions\Implementing the IObjectCLassValidation Class Extension Interface.