My theory is Helena found out Liz ran another DNA test on Aiden, so she retaliated by grabbing and faking Jake's death while Liz was about to read the paternity results. We know there was an unknown black limo with fake license plates. RC likes to bring people back from the dead as plot points only to turn around and either not use them or kill them off. Monica and Alan's children are all dead! If AJ/SK was not working out, then send AJ out of town on ELQ business or in a coma but there was no need to kill him, again!