Scott Ellinger pointed me to an excellent YouTube video this morning.
Toward the end of the video is a ten second segment showing the lowering of the colors for the last time at USTDC during the afternoon of April 26, 1979. Marine SSG D. J. Gemmecke lowered the colors. I'm fairly certain that the Navy officer standing in front of the group is Rear Admiral James Linder, the last Commander of the U.S. Taiwan Defense Command. After the ceremony, he and his wife Patricia went to the airport and departed Taiwan.
You can go directly to the flag lowering portion of the video by clicking on the following link: http://youtu.be/PRoe-ZNdiDo?t=9m8s
You can watch the complete video by clicking on this link: http://youtu.be/PRoe-ZNdiDo.