Yeah that might be true. They might have threatened him using Ngumbu as bait and I also suspect they fooled or tried to fool Msando that they won't kill them and were trying to get him to do something not so sure what. Obviously by this time Msando knows precisely why they were abducted...and might have seen through the ruse but the blackmail or was perhaps scared stiff he froze...especially when they started heading for Roysambu it should have been getting clear to Msando they won't make it...they would have to move them from Msando's car to their own car where I suspect Ngumbu was being held and in those CCTV the cops should have been able to identify the killers vehicle....based on footage where both cars are seen in multiple places...this info they might be keeping to themselves to avoid the killers taking countermeasures to destroy relevant evidence...