Stick the bloke who committed the foul in goal for the penalty.
Someone said Rugby, what about 15 mins in a 'sin bin' for every penalty, saves ruining a whole game early with 10 men.
I think the Rugby sin-bin had to be introduced because of an unintended consequence of an earlier change. Tries used to be three points plus two for a conversion and penalties/drop goals also three points. Someone had the bright idea of encouraging players to go for tries rather than kick goals by increasing the value of a try to four points and now five. Of course that just encourages players to cheat to stop tries so now we need a sin-bin to stop that.....
The way I think about it is that if the punishment for any ofence is much higher than the gain from carrying it out then there won't be any offences. So I would go with harsher punishments every time.
..... lets use it.
So HG Wells was right!