The would-be assassin who Elizabeth shot to save Nesterenko: was that Tatiana? It looked like her but I wasn't sure. They showed her in the 'previously' section so I think it was her.

It was Tatiana, I'm sure. I thought it was odd at first, but then I remembered her bitter comments to Oleg about how her career was ruined by him. She never did rise above the level at which she might be expected to go out and assassinate someone.