Carolina Panthers quarterback Cam Newton faced criticism from sports pundits on TV and Twitter on Sunday night for abruptly leaving a news conference following his team's 24-10 Super Bowl loss to the Denver Broncos. 

The visibly dejected Newton, who led the Panthers to a 17-1 season and was named the NFL's regular-season MVP, gave only brief answers to reporters' questions before walking out of the news conference, saying, "I'm done." 

Some commentators and reporters called out Newton for his behaviour at the news conference 

Among Newton's critics was actor Rob Lowe, whose sarcastic tweet drew a great deal of attention

People on Twitter, however, weren't about to let Lowe call Newton a bad "example to kids," without reminding him of his own history 

Some of the criticism of Newton had a racist tone, including a tweet from former NFLer Bill Romanowski, who referred to Newton, 26, as "boy" 

Romanowski deleted the tweet and later apologized 

While Newton's critics focused on his behaviour at the news conference, his defenders pointed to the sportsmanship he displayed to the winning Broncos quarterback, veteran Peyton Manning, immediately after the game at California's Levi's Stadium. 

Manning himself, appearing Monday morning on Today, said Newton "couldn't have been nicer to me. He was extremely humble. He congratulated me, wished me the best." 

Some said Newton's dour demeanour was aimed strictly at the media 

Newton previously faced criticism from many in sports media for being too exuberant in victory 

Many expressed sympathy for the man