He made half a mistake, which we could have rectified before they scored.
I doubt any footballer has ever had a faultless display in the history of the game.
Stones will be disappointed with himself when he sees it back. He obviously didn’t see the picture at the time and all he can do is learn from it and not do the same again, if possible.
This doesn’t make him an amateur, or any other hyperbolic adjective you want to choose.
Our forwards and midfielders made more mistakes today than our defence. That’s why we drew.