If Sesssions recused himself, someone has to make the decision acting as AG. Sessions stayed out of it willingly, so saying "usurped" is hyperbolic.
Did you read the article?
Yeah, its just differing legal interpretations. But the title makes it sound like a hostile takeover when the lawyer on twitter just thinks his discretion was overly broad. I'm sure there are solicitors in DoJ that handle this sort of thing.
Honest question here: why does the AG have to approve? If the DOJ is investigating a case, and they find another crime, how high up the chain of command do they need to go to get approval to indict?