Roger solely owns and lives in a house in Sydney. His employer sends him to work in its New York office for one year. Before leaving, Roger advertises his house for lease on the internet at "$600 per week all inclusive." The advertisement says "please contact my sister, Carol, to arrange inspection." David contacts Carol and says "I would like to rent the house but cannot afford $600 per week. Would $500 per week be acceptable?" Carol does not consult Roger but three days later she rings David and says "my brother will take the lower rent." Two days later David and Carol sign a 12 month lease over the house. When Roger discovers what has happened he refuses to accept the lease as valid. He says it was not signed by him, only by his sister Carol (who is not a part owner of the house) and he did not authorise her to accept a lower rent.

Would David have any rights in this situation or can Roger refuse to recognise the lease? Explain WHY or WHY NOT