Från noveliseringen verkar det helt klart att Krennic försöker att demoralisera Galen; Galen vill uppenbarligen inte att de andra ingenjörerna ska betala för sina handlingar, så Krennic har dem dödade för att visa sin kontroll och konsekvenserna av att korsa honom (betona min):
Galen took action at last.
He dashed between Krennic and the engineers, spun about and nearly slipped on the wet platform. "Stop," he cried, again and again, spreading his arms as if he could block the troopers' shots. "Krennic, stop. It was me. It was me. They have nothing to do with it."
Krennic looked into the face of the man he'd befriended long ago. He waited.
"Spare them," Galen said. Drenched and tired and wild-eyed, he looked like a man whose genius had deserted him.
Krennic crooked a finger at Galen. As if reluctant, the begging man stepped back toward Krennic.
"Fire," Krennic spat.
He didn’t watch the crimson bolts flare from his troopers’ rifles, didn’t bother glancing at the bodies of engineers tumbling to the ground and sizzling in the rain. His eyes were on Galen, and he saw the explosion of shock and fury in the scientist's face — saw him try to hide it the next instant behind a mask of iron.
But they were long past hiding things, and Galen should have known better. Krennic swung his fist in a tight arc and felt the back of his hand strike Galen’s cheek and chin. Galen staggered and dropped to his knees.
Rogue One: A Star Wars Story - Official Novelization Chapter 11
Även om det kan tyckas något utslag att utföra ett team av förmodligen begåvade ingenjörer, kämpar imperiet inte för att hitta nya rekryter. det finns alltid fler ingenjörer.
