My guess on not releasing this footage may be that the UNC does not want to rub it in the face of the Kim regime that one of their soldiers defected when they have been quiet recently:
The United Nations Command has put off a plan to release video footage of a North Korean soldier’s dramatic escape across a jointly patrolled area in the heart of the Demilitarized Zone.
The soldier defected to the South on Monday by driving a military jeep to the line that divides the peninsula, then rushing across it under a hail of gunfire from his former comrades.
The defector was severely wounded by the gunfire and has been hospitalized. His doctor, Lee Guk-jong, told reporters his condition was stabilized after a second operation on Wednesday, but he was riddled with parasites that were complicating his recovery.
Officials with the UNC, which is commanded by U.S. Army Gen. Vincent Brooks and has authority over the Joint Security Area, said earlier this week they would make public footage from surveillance cameras that monitored the border dash.
But the UNC issued a press release Friday summarizing already-known facts of the case and saying it will not release more details or material until an investigation is completed. [Stars & Stripes]
You can read the rest at the link.