Series 9 Episode 8 discussion

[HellsBells]

When Lucas is talking to Ruth, he said he been so careful, hiding his real identity. So why did it take Beth only a couple of hours to find a picture of the real Lucas North. Surely Lucas would have erased every file once he had access to MI5 data.
And back to an idea I posted before, why didn't Lucas just kill Vaughn the moment he saw him, considering Lucas was really evil John. Come on writers TOO MANY HOLES!!