Personally, I would be angry if someone create a thread against me without showing any real evidence of their claim.
I have explained my position and I still think it is a fair one.
I would say, it is better to lock the thread and keep your eyes on his account for now and then open the thread again if you find something suspecious.
I though about it but I think prevention is better (in case I am right), besides that there is no need to be angry or anything, I expect the same treatment for myself if I respawn after 4 -5 years.
As other forum members already mentioned, it seems this member did similar things before,
I think we can tolerate one reputation topic every 4-5 years, specially if the account is reputed with high trust ratings.