Ogden Greeley (No. 40) - S8-E8
Factual error: During the scene in a London bar, the emergency exit sign is red (and not green as required by UK law). The signs adjacent to the toilets are unlike the ones regularly seen in the UK, as are the US style light switches and a 110v power outlet in the ladies' toilets.
Answer: The man Red killed, Sam Scott, was Lizzie's adoptive father, not her biological one. However, at that time Lizzie (and thus the audience), was led to believe her real father abandoned her and her mother, so expect more secrets to be revealed how her real father actually died (or if he's even actually dead).
Bishop73