If a player deliberately kicks the ball towards his (or her) own goalkeeper and the goalkeeper deliberately handles the ball, thus denying the opposing team a goal or an obvious goalscoring opportunity, the restart is an indirect free kick from where the offence occurred, bearing in mind the special circumstances covered in Law 8. If the referee believes that the goalkeeper knew that without this illegal intervention, the ball would enter the goal, the referee could take action. The goalkeeperâs action could be considered as unsporting behavior. The argument would be that the goalkeeper could have chosen not to handle the ball deliberately but rather to use another part of his body to change the path of the ball. In short, an indirect free kick and a definite caution is the correct action to take if, in the opinion of the referee, the goalkeeper knew that without the illegal intervention the ball would enter the goal.
The almighty Graham Poll explains all. http://www.dailymail.co.uk/sport/football/article-2269562/Graham-Poll-Back-passes-dont-merit-yellow-cards--Craig-Burley-know.html
Yeah but if you get 3 warnings and commit another foul and are called Fellaini, it's still not a yellow card!!!