I don't want to touch the stuff in this episode with a 10-foot pole. Just want to say it was interesting and I wasn't surprised it ended in a "tie." Though, like Christopher, I too noticed that Jamie and Adam called a slim difference between the sexes as a "win" for the men when the other similar differences were seen as ties. I too wondered if it was made clear to the subjects that the doll in the car-seat was to be treated as a real child. (Maybe it would've been more clear if they had used a child-sized crash dummy or a more realistically sized/appearing doll instead of the Raggedy-Anne looking doll they had here.
I wonder if Jamie was really sincere about having no emotional expression. I suspect that he and the other hosts have a tendency to play up the personas the fans expect of them, so that as Mythbusters they're kind of caricatures of who they are in real life. Then again, have we ever seen Jamie really show emotion before? We've seen him get irritated at Adam, but without much change in expression or tone.
Jamie clearly seems pretty lowly-expressive when it comes to his face, it even seemed that way in the early days of the show before they got typed into their "characters." There's been times on th e show where Jamie has shown expression of emotion but it's came from real, genuine, moments (like the look of "glee" he had when their first test of the rocket-car launched (in the pilot episode IIRC) and he simply can't just "look happy" on cue.
And, yeah, I saw Kari's "angry" look as more come hither/sensual than angry too. Maybe that's a guy thing? We're driven by desires and emotions and make us mis-judge things. That or there's a link between "angry" and "sensual."