Custom Validation

I’m adding onCustomValidation error handlers to my code as per the sample given in:
https://www.wix.com/velo/example/custom-validations
My query relates to the lines:
otherEmailElement.validity.valid = true;
otherEmailElement.validity.valid = false;

According to the API documentation, the validity object is read-only. Is this just a documentation error - see extract below?
“validity
Gets a ValidityState object that contains detailed information about the validity states of the element.
Type:
ValidityStateRead Only”

If program flow drops through an OnCustomValidation error handler without executing a Reject statement, does the element’s valid property get automatically set to true or do you have to explicitly do so as in the code examples above?