I think the distinction being made here is the difference from using statistical methods for determining overall guilt versus using statistical methods for determining specific facts about the case.
We use statistics to say that someone was or was not at the scene of a crime
(DNA testing doesn't 100% guarantee that a persons' blood is actually a match), for example. We don't make the leap that since they were there, "odds are" they did it, however.
The question in R v T that Bayes theorem was being applied to was a specific, factual one: whether a footprint could have been made by a particular shoe.
We use statistics to say that someone was or was not at the scene of a crime (DNA testing doesn't 100% guarantee that a persons' blood is actually a match), for example. We don't make the leap that since they were there, "odds are" they did it, however.