Hello Chris Lekkas,
I checked your code and I noticed the following:
1. By checking the validation control's display you decide whether to show or not the tooltip. If there were not validation errors you "prevent" the tooltip to show by args.set_cancel(true). You cannot hide the tooltip by using tooltip.hide() because it is still not shown.
2. Make sure that you have a function which shows the tooltip and is called when the validation is done.
I prepared a simple application which demonstrates the desired by you behavior. Please, find it attached.
the Telerik team