Garnett had his hand around Walker's throat after the Celtics' forward missed a potential game-tying shot at the buzzer. The two had to be separated by coaches and players at the end of the Knicks' 106-104 win over the Celtics.
"Heat of the moment," Walker said on Monday. "I just went and contested the shot. We got wrapped up, tangled up and, you know, the rest happened."
Walker and Garnett got into it after Walker contested Garnett's jumper from the right wing at the buzzer. After Garnett's shot caromed off the rim, Walker appeared to step toward Garnett and say something to him.
"I can't get into that," Walker said when asked what was said between he and Garnett. "We were in the heat of the game. It was a tough game throughout, it was a dog fight. Nobody wanted to lose. It just came to a head right there and it's over."
Celtics coach Doc Rivers said Tuesday that the officials missed the beginning of the play.
"You know what's funny, Kevin is Kevin, he gets in a lot of stuff. But I thought everyone missed the beginning of that," said Rivers. "No one noticed that the other guy actually reached out and hit Kevin on the arm. It's amazing how I watched that for two days and I didn't see that one time -- [the highlights] would only show Kevin's reaction to it.
"No, I didn't think he would [get suspended]. Once I saw it I didn't think it was enough -- much ado about nothing, really. But I was amused by the attack on Kevin, when no one noticed. The guy just missed the shot, and then the other guy hits him on the shoulder, then [Garnett] turns. That's what made him turn around. So I was amused by that."
As Walker was leaving Madison Square Garden following the game, he saw Garnett heading toward the Celtics' bus.
He approached Garnett to say that he had no hard feelings.
"We shook hands, I talked to him ... I chopped it up with him. I still respect those guys," said Walker, who played a little over one season with Garnett in Boston.
Walker later added, "I have a respect for KG."
ESPNNewYork.com's Ian Begley and ESPNBoston.com's Chris Forsberg contributed to this report.