According to the article it's because the appeal was delayed.
In re Winship (1970), the doctrine of reasonable doubt applies to all the essential facts necessary to prove a crime.
I need to check, but I think the Winship decision reads ...
"(We) explicitly hold that the due process Clause protects the accused against conviction except upon proof beyond a reasonable doubt of every fact necessary to constitute the crime with which he is charged."
Amen to that.