You know, it is always too easy for lawyers to be glib about procedural defaults that are based on really stupid, technical rules, that would be difficult for a layman to know.
Well, I submitted a FOIA request for mug shot from the Bureau of Prisons about three weeks ago. The letter was three pages long, and was replete with citations to case law, and included some original legal arguments as to why prisoners who had their convictions reversed by SCOTUS should also be released. I spent some time working on it, and had a few Harlan colleagues edit and revise it.
Today I got a letter back from DOJ. This member of the Virginia Bar and Magna Cume Laud law school grad forgot to sign the letter. They returned my request as Incomplete. I just mailed it back, with my signature affixed.
Fortunately, there was no time limitation, but my request–had there been one–would have been time barred.