Filtering using node reference URL widget

I am using node reference URL widget to provide filtered inputs for certain fields.

Let me give you an example. Assume three content types: School, Student, Race. Both Student and Race have a node reference to School using "Reference from URL" widget. In addition, Student has a node reference field to Race.

I first create School A. Then create all races in this school, e.g. Race RA1, RA2, RA3 and then create School B and Races RB1, RB2.

I also created a view, say "select_races", which filters all Races and uses School as an argument.

Student has a node reference field to Race which uses "select_races" and passes its argument (e.g. School A). When we go to School A's page and click on the link to create a Student, argument (School A, in this case) is passed into the view and "student race" field only lists "RA1, RA2, RA3". So far so good.

But once I save this node and edit it later, "select_races" fails since School is no longer an argument to the view. The node reference field to School is uneditable (since it is set that way), hence School A information is there but not passed to the view.

Any idea how I can fix this? I hope it is not too confusing.