“(4) In proceedings against a person for an offence under subsection (1) it is a defence that, at the material time– … (b) an application for a licence had been duly made in respect of the house under section 63, and that notification or application was still effective (see subsection (8)). (5) In proceedings against a person for an offence under subsection (1), (2) or (3) it is a defence that he had a reasonable excuse– (a) for having control of or managing the house in the circumstances mentioned in subsection (1) …”
“(4) In determining the amount the tribunal must, in particular, take into account— (a) the conduct of the landlord and the tenant, (b) the financial circumstances of the landlord, and (c) whether the landlord has at any time been convicted of an offence to which this Chapter applies.”