Star Trek III: The Search for Spock (1984)

Revealing mistake: When Kirk and Kruge are fighting, a piece of the cliff breaks away and wiggles down the side of the cliff rather than falling like a rock. (01:22:55)

[The crew watches the Enterprise burn up in the Genesis planet's atmosphere.]
Kirk: Dear God Bones, what have I done?
McCoy: What you had to do, what you've always done, turned death into a fighting chance to live.

Trivia: On the backside of the DVD near the bottom is a series of six images purportedly from the movie. The second image shows the crew in uniform, including Mr. Spock, standing in the Federation Council chamber. This image comes from the movie Star Trek IV: The Voyage Home (after the crew has returned to Earth and is waiting to hear the Council's judgment).

Question: The data for Genesis are transmitted to Kruge, however, later, he has one of his men murder David Marcus (Admiral Kirk's son) and demands Genesis from Kirk. He had already downloaded the data, so what additional information did Kruge want? (00:09:30)