The Queensland Succession Act 1981 notes the following so if both husband and wife die simultaneously, the younger of them is deemed to have died last, but in many wills, there is a requirement for the beneficiary to survive the deceased by 30 days so if this were the case, the house would pass to the beneficiary listed in the will who survived the husband by 30 days.
Please note that my answer is a hypothetical answer to your hypothetical question and does not constitute the provision of legal advice.
SUCCESSION ACT 1981 - SECT 65
65 Presumption of survivorship
Subject to this Act, where 2 or more persons have died in circumstances rendering it uncertain which of them survived the other or others, such deaths shall (subject to any order of the court), for all purposes affecting the title to property, be presumed to have occurred in order of seniority, and accordingly the younger shall be deemed to have survived the elder for a period of 1 day.