It was a well taken strike, coming after he rescued Ayoze Perez's deflected shot before turning and hitting the ball low past Lukas Fabianski and just past the far post into the net.
Carvalhal said: "After the game, I don't know if we have achieved one point or lost two, really, especially when I arrive in the dressing room and my players are really upset because there was the feeling that we could win this game".
"I didn't like the last five minutes when we were making some wrong decisions and giving them the chance to play on the counter-attack".
Benitez said: "The new world of football is very expensive". He is doing that.
The former Liverpool and Swansea man Shelvey has been strongly linked with a transfer to David Moyes team during recent weeks with reports suggesting that Benitez would sanction a move if he received an offer in the region of £12 million.
Benitez concedes that Joselu - who cost a reported £5million from Stoke City - could chip in with more goals, but says the Magpies would have to pay much higher fees to secure a better alternative.
"Still he can improve things, but in terms of mentality, character, he is someone who is going in the right direction and that is the main thing for us and the club because you don't have too many centre-backs around with this presence and this character".
His strike puts him out in front on the list of the Magpies' top scorers in the league, with Dwight Gayle, who passed up a handful of goal scoring opportunities before being replaced by the Spaniard, sitting on three goals.
Newcastle pressed for a victor without creating many chances to find to it, and Swansea would have stolen the points had Wilfried Bony not seen a goal-bound effort cleared with Darlow stranded, the draw making it just one defeat in four in all competitions for Carvalhal, a run that will provide little solace for the Portuguese given the team's predicament.
"Then they have to work hard. His attitude and behaviour has been positive the whole season".