Looking at the code, it seems that only one error message is displayed at a time. However, it would be nice that other error messages took precedence over the 'Required' error message. For example, if I have a property of type 'integer' that is required and the user types letters, ideally the user would see a Not a number error message and not a Required error message.
This is currently what I'm seeing:

I have put together a plnkr that shows this.