sonak's transporter ghost wrote:
The shift in the planet's orbit happened months later. Why would Kirk be like "hey, I should really go check on the insane despot who tried to kill me and hijack my ship just to make sure he's doing okay?"
Because you want to make sure the insane despot doesn't figure a way off the planet. Hell, you wonder why they didn't drop a probe in orbit before leaving to monitor the system.
Kirk is my favorite Trek character, but he made quite a few mega-blunders over the course of Trek.