Mane has no chance whatsoever to win the ball and he just sticks out his leg in the hope that he will be able to initiate any kind of contact and then fall down on the grass. If it had been given, it would have been similar to the penalty Everton were awarded at Anfield when Calvert-Lewin pulled the handbrake, once he realised that he didn't have a goalscoring opportunity, and just waited for any kind of contact in order to go down. But as far as i remember, Klopp was furious about that one and rightfully so.
I just hate it when attackers try to do this and i can't understand why pundits, who like to brag about how tough and manly the game was back in the day, almost always hide behind the "was contact, is penalty" line of thought.
Of course, Carragher is right. After all, he's a defender himself and he can sympathise with Fellaini who's in front of Mane and he's just trying to position himself. As for Gary, i really expected nothing more from him after Mourinho's comment that "some pundits couldn't resolve their own problems when they were managers but now they have a solution for everything". In the post-match interview, Mourinho went one step further and named him too. And despite Mourinho's belligerent nature, someone should advise Gary that paying lip service to your fiercest rivals doesn't make you neutral.