I just cannot imagine the special prosecutor putting him through three more days of misery if they are not going to arrest him. They have evidence. Stippling...gsr..the tapes..tests of voice on tapes...I cannot imagine what other tests they might be doing.
Yes, they have the evidence, but they probably need the time to get all their ducks in a row to present it to the public, and also to prepare for the reaction to the decision. They can't afford to be sloppy about it.