Re: Episode of the Week : The Enemy Within
I read the uniforms had to be washed but the insignia (and likely the braiding as well) removed first. They were rushed and yet overlooked to sew the insignia back on. When it was noticed they didn't have time to go back and reshoot it and figured next to no one would probably notice anyway. I know I didn't the first few viewings.
STAR TREK: 1964-1991, 2013-?