See, I would have been right to give it!
Seriously, even though that looks pretty cut and dried*, it is so close that no one picture or video angle that I have seen is absolutely conclusive when considered among the many others, although several appear to be conclusive when taken on their own.
The point is that it was in the 23rd minute; regardless of the injustice, who knows what would have happened if it had been given. You cannot say that it cost Wales the game more than the squandered chances in the last 10 minutes.
* And it really really does.