Ah— no, I mean... I think that it's more likely to be the VIPs. Mahiru said that since there's only one body, it means that only one group of people could have been responsible for Malik's death - either the VIPs, or the detonator and the person with a detonation key. But if the detonator was responsible... it would mean that the medical team managed to successfully protect the VIP target on the very first night. See? That's what seems unlikely.