John and Andrew were very close friends. In 2018, during a discussion of their respective futures, they decided that they would each execute a will in terms of which they will benefit each other. Both were unmarried and neither one had descendants or immediate families to whom they could bequeath their estates. Shortly after the discussion, John drafted a will on his computer and e-mailed it to Andrew. In this will, John revoked all previous wills and left his entire estate to Andrew. John had previously, in 2015, executed a will in terms of which he had bequeathed his entire estate to the Animal Welfare Society. Eight months after drafting the second will, John died without him or witnesses having signed it.

Advise Andrew with regard to his rights to inherit John's estate. Refer to relevant case law.