Ignoring Robbie's red herring concerning who makes decisions on behalf of the team where to kick the ball, what is interesting is that in 40 posts there have been recommendations to use all three of the possible sanctions originally posed. Consistency has not shown itself therefore.
What is clear is that there is no specific sanction in law so it becomes a matter of judgement by the referee as to the consequences of the kick in relation to the precise circumstances of the game. Law 21.5(b) requires that a kick at goal must be taken once that intention has been stated; why so? Is it to allow the defenders to position themselves to best defend the kick; possibly to prevent the defenders from distracting the kicker by establishing an appropriate benign disposition at the kick or is it to prevent the attacking side from using some ploy, such as a kick to the wing knowing that the defenders are clustered near the posts, to pop the winger over for a potential 7 points vice the three points on offer?
Making the kicker take the kick again does not work for me as he has infringed and arguably has done it intentionally; it would smack of a second bite of the cherry. Calling time while infering that the kicker may have sliced his kick is probably wrong too; not even I am that bad a kicker. The kicker has infringed (it is a game, remember) and the defenders are entitled to reap the benefit, just as you might award a scrum when a tap kick fails to move the ball a visible distance. As Ruling 2 of 2010 requires all options to be offered to the non kicking team should the ball be kicked directly to touch at a restart when time has expired, so should the sanction for an improperly taken kick be awarded in this case.
I would suggest that the opposition should have an opportunity to do do something useful with the ball until it next goes dead before time is called, particularly, as in this case, where a single score would have changed the outcome.