Discovery is run largely by attorneys, and the court and the judicial process depend upon honesty and fair dealing among attorneys. Thus the court may impose appropriate sanctions on a party that, without substantial justification, fails to disclose information required by Rule 26(a) or 26(e)(2). A failure to disclose under Rule 37 encompasses both the destruction of evidence, or spoliation, and untimely production of documents and information required to be produced.
In re September 11th Liab. Ins. Coverage Cases, 243 F.R.D. 114, 31-32 (S.D.N.Y. 2007).