My friend has moved out of her rented house as it is not fit to live in.?

ie no internal doors downstairs, light switches hanging on wires through ceiling, bare stone floors faulty unserviced gas boiler, wet ceilings holes in roof need I go on. He refused to do the work until 4 weeks arrears were cleared, but the house was unsafe, as above.He threatened to make the house worse if she kept complaining. She was afraid . She has moved out, owing the back money but he has her bond. Leaglly what should she do. He says he will take her to court, but she took photos of the internal of the house in the state . What will happen in court. Could a judge find in her favour because of the state of the house? UK Legals please answer if possible, or Local Authority officer.