My friend broke up with her verbally abusive boyfriend back in October on bad terms and he moved out of their shared flat without giving her any notice. He left her with all the bills and rent to pay until last month when she found a cheaper place to live. She just received the deposit they both put down for the old place (totaling £825) and she's concerned he may ask for his half back. Should she give it to him despite what he owes her anyway? Is she legally required to give it to him?