Killing the son of a policeman doesn't make sense when his dad the policeman is already dead, you gain nothing from it and a crime family would be thorough and have at least had dave investigated or followed by their men. Would be pretty obvious dave was harmless so acting against him would be a waste of resources and could risk getting noticed by the police. Also Thanatos explains how the vault works using dna as authorisation for the vault to actually work. Orlando can work it because his dads dna was added but you never get an explanation on how daves dna is in it.
ahh yes, I'm very curious about that part as well, I get that Oswin vould have had gotten Orlando's father's scales, But we still don't know how they got Dave's (the father) dan as well... Unles... Nah it couldn't be... Could it...? What if Dave (the father) was the survivor of Oswins experiments for his "cure all" medicine...?
Then we'll all wait and see until the answer comes further and love your theory tho
actually it makes sense that
Dave (dad) was the survivor of oswin's experiment. And that Oswin HAD to make sure all the patient's he was testing on wasn't allergic to the vaccine he made. And he took fur of Dave(dad). Also explains why he became a police officer in the first place.