Just to be clear, Trump at no time used the word yes. Here it is transcribed:
Wallace: "You have repeatedly criticized the vice president for not specifically calling out Antifa and other left wing (Trump says here, that's right) extremist groups. But are you willing tonight to condemn white supremacists and militia groups (Trump says here, sure) and to say that they need to stand down and not add to the violence in a number of these cities as we saw in Kenosha and as we’ve seen in Portland."
Trump: Sure, I’m willing to do that.
Wallace: Are you prepared specifically...
Biden: Do it.
Wallace: Go ahead sir.
Trump: I would say, I would say almost everything I see is from the left wing not from the right wing.
Wallace: But what are you, what are you gonna, what are you sayin...
Trump: I’m willing to do anything. I want to see peace.
Wallace: Well then do it sir.
Biden: Say it, do it, say it.
Trump: You wanna call 'em, what do you want to call 'em? Give me a name, give me a name, go ahead, wha... who would you like me to condemn. Who?
Wallace: White supremacists and right, white supremacists and right-wing militia.
Biden: The Proud Boys.
Trump: Proud Boys? Stand back and stand by. But I’ll tell you what, I'll tell you what, somebody’s got to do something about Antifa and the left because this is not a right wing problem this is a left wing.
So clearly Trump never used the word yes, he used the word sure. Same thing? Maybe, but he never said the word yes which for some is more definitive. And Wallace asked him specifically if he would say that they (the Proud Boys) need to stand down, and to not add to the violence and Trump did not do either. Instead, in addressing the the Proud Boys, he simply stated that they stand back and stand by.
Just to be clear.