The thing is, the Bechdel test isn't just a barometer of the strength of female characters — it's a test of the writer's interest in dealing with female characters in the first place. And though I liked "Pacific Rim" a lot and liked Mako particularly, I'm compelled to ask why she was the only female character in the piece? Why couldn't Raleigh's brother who dies in the opening have been his sister? Why couldn't the Australian father-and-son team have been a father-daughter or mother-son or even mother-daughter team? Why couldn't either of the scientists have been women?
I don't know that any of those changes would have made "Pacific Rim" pass the Bechdel test (because I don't know that any of those hypothetical female characters and Mako would have had a conversation). But I think any of them would created a more interesting foundation of character story, and that's what the Bechdel test is about.