The infamous competition bottle that had diacetyl was from a Dutch bottle of pils I bought in the supermarket. I needed that bottle because it had the required bottle for the competition in the Netherlands. The beer was carefully poured away before I rinsed and cleaned the bottle. So I don't think it's pedio. It was an act of God.
Diacetyl is only one indication of a pedio infection. Denial is the other.
I blame your gelatin addition procedure.
Its only MY procedure when it works. When it doesn't work, its just something I read on the Internet