This one felt extremely cheap, to the point where I was expecting to be subverted there, with the dispatch officer surviving despite his sob backstory. Inami and others in the 100th Assault Girl Cavalry Brigade got to know about the mission to kill Tsukiko, so did the ex-hyena mercenary, didn't they? Even so Takigawa did not kill them.
There is even nothing to leak there. The dispatch officer knew absolutely nothing that the Prophet and many others in the field didn't know. So this entire thing seems very, very forced. The author could simply have outright said "please fell bad".
The only explanation I can think about is that the Prophet concluded that all those people knowing about the mission presents no risks to it, so no reason to bother, like that case with the sex toys girl, maybe concluding that they would all die or the mission would end before having any chance to leak critical information, while the dispatch officer knowing could ruin it, so he had to be taken out.