Fair point on there being a precedent, I'll concede that point.
But, I still think it's not simply Clara dialling wrong, this is the original incarnation before crossing the Doctor's timeline, so she doesn't have any concious/subconscious knowledge of him yet. Given that Moffat has had the "Silence will fall" thing going from the day 11 regenerated (Prisoner zero said it) and we'll only get the conclusion of that in his last episode.. I wouldn't put it past him to work that one simple point into a future story.
Or maybe I'm just getting used to the hundred and twelve continuing threads and repeated references that we've had recently. Maybe it would be nice to have a few of 12's episodes be entirely new, with planets, species and times we haven't seen before?