What Brady offered, but was declined by the NFL:

Specifically, it can be found at footnote 11 on page 12 [of NFL statement upholding suspension]: “After the hearing and after the submission of post-hearing briefs, Mr. Brady’s certified agents offered to provide a spreadsheet that would identify all of the individuals with whom Mr. Brady had exchanged text messages during [the relevant time] period; the agents suggested that the League could contact those individuals and request production of any relevant text messages that they retained. Aside from the fact that, under Article 46, Section 2(f) of the CBA, such information could and should have been provided long before the hearing, the approach suggested in the agents’ letter — which would require tracking down numerous individuals and seeking consent from each to retrieve from their cellphones detailed information about their text message communications during the relevant period — is simply not practical.”
http://profootballtalk.nbcsports.com...text-messages/