I too was surprised that there was no mention of Russ. Landlords have to have 2 full months with no money for rent being paid, before they can take the tenants to court for eviction and repayment of money. If the tenant pays some money towards the rent, (ie, Lily's half) then I think they'd need to give notice for the end of the fixed term, and then use the deposit, and take it to court for the remaining monies owed.
The bailiff said she was from the High Court. The High Court is used by landlords to fast track payment.
Lizzie certainly should be having serious words with Russ about why he wasn't paying his share.
I hope there's nothing nefarious about Len, I quite like him, and it seems he's a good influence for Freddie.