Is a disclaimer by the only life tenant of a testamentary trust void ab initio?

The rationale in McGavin v. National Trust Co., supra, for why the variation of trusts legislation is not engaged, is that a disclaimer by the only life tenant of a testamentary trust results in the gift being void ab initio. As a result the trust fails. The remainder beneficiaries take not as beneficiaries of a trust, but because of the failure of the trust they are the beneficial owners of the property and, subject to court approval when the class of beneficiary is not closed, the remainder beneficial interest is accelerated. The court application is not to vary or revoke a trust, but simply to determine if the testator expressed an intention to the contrary with respect to acceleration of the beneficial interests.