The Canaries midfielder was issued with his marching orders in the 81st minute after an off-the-ball incident involving Magpies striker Loic Remy, who also received a red card for his part in the incident.
Has he pushed him in the chest? Yes. Is it overly aggressive? No. Is it aggressive? To a degree
Earlier, Newcastle’s France international had come closest to breaking the deadlock after the striker hit the post and crossbar at Carrow Road – and Hughton conceded that the Magpies had the better chances to score.
“Newcastle were very good and better on the ball than us. We got to grips better in the second half,” Hughton said.
On Johnson’s red card, the Canaries boss added: “Incredibly soft. If the lad Remy doesn’t get sent off, neither does Johnson.
“Has he pushed him in the chest? Yes. Is it overly aggressive? No. Is it aggressive? To a degree.
“It’s something you’ll see week in, week out.
“You’ll remember a couple of weeks ago Wes Hoolahan was grabbed by the throat at Crystal Palace and there was no red card there. So we’ll look at it again and make sure we make the right decisions.
“My first gut feeling was that it was wrong.”
However, Newcastle manager Alan Pardew pointed the finger at Johnson after the midfielder’s dramatic reaction to his clash with Remy.
“There is a bit of pushing and shoving, the players have come together, there is probably just enough for the referee to send them off,” Pardew said.
“But Johnson’s reaction, that he got a headbutt when he did not, was the catalyst for them both to get sent off.
“He made such a drama out of it, he should be ashamed of himself really.”
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