Having enjoyed the part biopic of liberal iconic judge Ruth Bader Ginsburg, “On the Basis of Sex” (I rated it as 7/10), I was ruing the fact that I’d missed the short Australian season of the more life-encompassing documentary “RBG.” Luckily it has popped up on free-to-air here, so I’ve taken a look. And this is a most fascinating documentary, especially for a non-American who is only vaguely aware of the huge role Supreme Court judges play in political, let alone judicial life in the United States. Ginsburg’s pivotal role in initiating a revolution against discriminatory legislation is interesting enough, but then her more recent role as sensible dissenter on the Supreme Court, during a conservative phase of the country, is most absorbing. The documentary itself is competently unfurled, with plenty of modern-day, frail-but-unbowed Ginsburg on show, and some good interview material. But I sensed something missing. The key moments of drama in Ginsburg’s past are explored but not deeply and something about the “plotting” of the film renders it unexciting. In an era when documentary makers can turn fact into riveting entertainment, “RGB” is interesting to watch but fails to catch hold. One to see but not a highlight.