Reading between the lines, the elders destroyed the letter on the basis that under DPA laws they had no need to keep it. This most likely would either have been after the DF was confirmed by the branch or at the end the year as a result of the yearly reminder to rid the files of as much "superfluous" paperwork as possible. There is of course the chance that once the legal action was initiated the file was checked and purged either unilaterally by the local elders or on instruction from the branch or CO. Who knows...?
As I say, there is plenty of evidence of typical kangaroo tactics by the elders on the JC but for me the question still remains as to what were the circumstances that lead to an accusation being made and could this undermine Mr. Otuo's position and credibility?