How has the changed circumstance rule been interpreted in this case?

Father next asserts the court misapplied the "change of circumstance" standard, citing Montenegro v. Diaz (2001) 26 Cal.4th 249. Father quotes from that case to the effect that `"[t]he changed circumstance rule is not a different test devised to supplant the statutory test, but an adjunct to the best-interest test.'" (Id. at p. 256.) He omits the remainder of the quotation: `"It [i.e., the changed circumstance rule] provides, in essence, that once it has been established that a particular custodial arrangement is in the best interests of the child, the court need not reexamine that question. Instead, it should preserve the established mode of custody unless some significant change in circumstances indicates that a different arrangement would be in the child's best interest.'" (Ibid.) And in Montenegro, the prior orders were not final orders, as they were here. Father's argument that because the judgment was entered into by stipulation it was somehow not final is unsupported by authority and contrary to law. The court properly applied the changed circumstances rule.