what you mean you were not as tall as Gea? he is 6ft 4in (193cm) !!
sure there is an element of risk when buying any kid, this is why when you see a proven one, you reduce those odds and pay more.
SAF said it after the game, the goal was bcz defenders didn't helped Gea , i remember when we had taller players and Rio and Vidic fit we had many clean sheets with Gea who hardly made a mistake, but if you have only 2 tall players in whole 11 players in the pitch, and both are young, with a young unexperienced GK behind them, positioning and organization of team in set pieces is just a disaster, and oppsite team will have advantage in number of tall players .. tbh yesterday our CBs where making it harder for Gea to defend the ball, as they all gathered in same position with about 6-7 players overall blocking Gea, that is not how you defend a set piece, you sure try to give more space for GK to go out and take the balls. that will be fixed with more training and experience
Gea need to play and make mistakes .. it is part of learning process . Lindegaard is not perfect either ..
they should make mistakes, it is part of the process of learning to develop your skills