Poor old Danny Pink had no luck. First he accidentally kills a child, then he has to put up with the Doctor barging his way into he and Claras relationship, then just when things are looking up, he gets banjaxed by a Renault Megane. Clara and Danny Pink were very well suited to each other, so why not have her follow her beau into the hereafter by a similarly unceremonious method? Maybe they could have her accidentally electrocute herself while turning off a bathroom light with wet hands or fall off a barge or something. As much as Doctor Who is about fantasy, it's also about the realities of modern life; if there's one thing that scares kids these days, it's sudden, unexpected barge-death.