Do not blame the captioners for all errors
Not all the errors you see on the TV news are the result of mistakes made by the captioners. The captioners works under intense pressure, and it is quite possible that they make some errors. A good captioner normally does not make more than 2% errors.
Errors can also arise because the caption information is a very sensitive signal encoded in a small area inside the video. If the picture reception on your TV is not very good, you will invariably see some mistakes in captions due to the distortions of the caption signals.