The ex-Granada manager flew into a touchline rage when he spotted his opposite number complaining.
"What are you protesting?" he is seen to say. "You've spent the whole game complaining!"
When Neville attempted to diffuse the confrontation by insisting he was simply asking how much stoppage time was to be added, the 58-year-old waggles his finger before cursing: "Son of a whore!"
Neville was at pains to play down the incident when he questioned on it in his post-match press conference.
"I'm a bit confused with this, I think he's misunderstood, it's something that can happen with the tension of the last few minutes.
"He thought I was protesting for a free kick but the reality is that I hadn't seen the board saying how much stoppage time there would be and I was asking the referee how long was left, I wasn't asking for a foul because it was so clearly a foul.
"It was a mix-up. Nothing more."
Gary Neville's job was reported to be under threat following a run of winless games that included a humbling 7-0 defeat to Barcelona.
But Valencia president Layhoon Chan has offered his backing to the England assistant coach, insisting his job was never under threat.
"You cannot dismiss a coach for a poor run when the players believe in him - they believe in Gary Neville," she told Spanish newspaper AS.
- Telegraph