Here is an example which demonstrates the issue I am having. http://dojo.telerik.com/EcEgo
To reproduce the issue, delete the value in the numeric text box and than click validate button. You should see the error message in the <span data-for="UnitPrice" class="k-invalid-msg"></span> which is defined by me in the DOM. After than click inside the numeric text box (focus) and then click outside the numeric text box to lose focus. You'll see 2nd validation message to appear.
My question is - why this happens? Am I doing something wrong or this is a defect in NumericTextBox?