Business Validation Logic Code Smell

Question

Consider the following code:

partial class OurBusinessObject {
    partial void OnOurPropertyChanged() {
        if(ValidateOurProperty(this.OurProperty) == false) {
            this.OurProperty = OurBusinessObject.Default.OurProperty;
        }
    }
}

That is, when the value of OurProperty in OurBusinessObject is changed, if the value is not valid, set it to be the default value. This pattern strikes me as code smell but others here (at my employer) do not agree. What are your thoughts?

Edited to add: I've been asked to add an explanation for why this is thought to be okay. The idea was that rather than having the producers of the business object validate the data, the business object could validate its own properties, and set clean default values in cases when the validation failed. Further, it was thought, if the validation rules change, the business object producers won't have to change their logic as the business object will take care of validating and cleaning the data.

Answer 1

It absolutely horrible. Good luck trying to debug issues in Production. The only thing it can lead to is to cover bugs, which will just pop up somewhere else, where it will be not obvious at all where they are coming from.