Newcastle goalkeeper Tim Krul denied he waited in the tunnel to congratulate Sunderland striker Jermain Defoe on his stunning derby strike.
Television pictures showed the Dutchman's exchange with Defoe as they left the pitch at half-time, although Krul later insisted the images had been misinterpreted amid criticism on social media.
Sky Sports studio pundit Jamie Carragher also called Krul's conduct "a mistake," but Krul stressed he had not stepped out of line.
Krul told the broadcaster: "What I actually thought I probably can't repeat on television because it wasn't nice.
"It was a fantastic goal and everyone accepts that. What I actually thought was more in the region of, 'What a lucky guy he is,' but with a bit more venom behind it.
"Listen, I've been at this club for 10 years and I'm as hurt as anybody else, so whoever wants to put this negative light on me, it's not justified.
"I'm a Geordie. I've been here 10 years and I'm going home with a lot of pain in my heart. To see those travelling fans going back to Newcastle without a win again, it hurts me as much as them."
Carragher, the former Liverpool defender had said: "What he did was a mistake. I wouldn't do it -- I wouldn't want to see one of my own team do it.
"Everton-Liverpool -- I would certainly not be shaking an Everton player's hand if he went past me and scored a goal.
"He's waiting for him in the tunnel, he's smiling. You can't have that in any game but in a derby game? What's he thanking him for? What's he wishing him well for? I just don't understand it."
Newcastle head coach John Carver was quick to leap to Krul's defence, saying: "Let me tell you something about Tim Krul: Tim Krul is the most passionate guy about this football club.
"He has been here since he was a young player and he loves this football club, he loves the fans, but sometimes when somebody had a bit of brilliance like that, professional people appreciate it and maybe that's why that happened.
"He cares about the football club. He wears his heart on his sleeve -- he's the first one to speak up when it's not right, which is fantastic, in my eyes, so I have got no criticism of Tim Krul. He obviously appreciates a bit of skill because he couldn't have done anything about it."
He added: "We get slaughtered when we're not sportsmanlike, and when you see skill like that you have to accept it."
Carver said Netherlands international Krul had been a doubt for the game with food poisoning as his selection problems threatened to take a further turn for the worse.
Carver added: "Maybe I have run over -- it's quite appropriate, this -- 10 black cats. I don't know why, I'm just not getting the rub."