This is why Mueller may try to stall for YEARS.... as long as he pretends to have an open investigation he tries to postpone any Day of Reckoning for his own team.
Of course, at some point the DOJ/AG may finally come down hard on him.
If it became blatantly obvious that Mueller’s actions are in fact a delaying tactic a lawsuit could result in a federal judge issuing an order for him to end his investigation (aka “sh-t or get off etc etc).
A lawsuit would be the venue for that.