I think you are trying to reduce what is being said to a semantics argument, and it isn't. Whether data gathered from someone checking zones and seeing if plays are made is "inconclusive" as to a player's defensive ability regardless of sample size, or, whether you consider such data to be "inaccurate" in the first place is the issue. Some people will consider the underlying data based on zones and plays to be inaccurate - and I mean flat inaccurate.
That wasn't the comment - go back to page 2 and re-read it. It was specifically stated that the data was inaccurate in small samples. That is an improper understanding of the data. That elementary misunderstanding was further exacerbated by claims of "garbage in and garbage out" later. If you want to claim the data is "inaccurate" you need to claim that the data does not actually represent what happened.
To further my example - inaccurate data would be to count a one-armed man as a two-armed man. If that's the claim about the data, it hasn't been supported here. The mistake is fundamental - it was pointed out immediately by snepp and has since be reiterated by old nurse and several others. It is a simple, very elementary mistake that indicates a complete lack of knowledge of statistical terms.