Only the last line was tongue in cheek, the rest was serious - I know its the "given rule" but seems that sometimes its not fair, although the explanation for this case makes sense.
I understand the fault rule with regards it rear ending somebody, many years ago I went into the back of someone (gently) who went to go off a busy roundabout in commuting traffic and then performed an emergency stop.
However, the girl is a bloody idiot for using her handbrake to stop a moving car in anything other than a situation where her foot brakes have failed. I cannot get close to understanding what would possess her to do that, she'd never have been taught it... Just weird.