I'm using the same form for insert/update. Let's say I'm in the middle of an inserting an object, and have already hit submit, I've got some errors showing and the validation mode has switched to on key up from on submit, and then I don't fix my errors. Instead, I go to edit another object, the field values update to those of the new object, but the old error messages stay in place, and validation mode doesn't revert back to on submit, so I press a key in the field and it reruns validation on the current value of the field and then the old error goes away.
I think you need to reset the validation state when the doc is switched out for another doc, but I'm not sure exactly how you would detect or define "switched out".
I would think it's a fairly straight forward fix to ensure validation is rerun when a field value changes due to a change via the doc attribute, because it is just another avenue thru which a field value can change. Therefore, this would be a great first step.
The second part, of knowing when to revert back to on submit, from on key up, because it is a different doc, might be harder to detect, but I figured I get the ball rolling on that conversation.