Bearing in mind that Stadhart was at best running in a straight line parallel with the left hand edge of the penalty box and would have been about about 6 yards from the by line if he had been allowed to catch the ball.....
Extract from the FA Laws Of The Game
Sending-off offences
A player is sent off and shown the red card if he commits any of the following seven offences:
is guilty of serious foul play
is guilty of violent conduct
spits at an opponent or any other person
denies the opposing team a goal or an obvious goal-scoring opportunity by deliberately handling the ball (this does not apply to a goalkeeper within his own penalty area)
denies an obvious goal-scoring opportunity to an opponent moving towards the player’s goal by an offence punishable by a free kick or a penalty kick
uses offensive or insulting or abusive language and/or gestures
receives a second caution in the same match
I'll leave you to decide whether you think the keeper contravened any of those.... and also how happy you'd be if the same happened to Turner and he was made to go...