And that led to having to operate within much smaller zones.
"Coach Leach had to really pick and choose. The things he would normally call weren't available because Halliday was under so much pressure -- you need time to find those receivers in the zones and that's what beats them. That's why you saw what you saw."
But Walden also said while CougFans will lament Halliday's interceptions, there was more to his night.
"I felt Connor did a good job in the second half managing the game under those circumstances, and especially compared to the first half," said Walden. "Stats will show he didn't have a good game but I thought he managed it well and as a former coach I can't emphasize that enough. Another thing, you don't want to give up on what you're trying to do too fast -- they turned the page in the second half and moved to the better things and that was right when they should."
And that's part of why Walden gave Leach and staff two enthusiastic thumbs ups for Saturday's win.
"I truly did not see one coaching error, in my opinion, that would even be worthy of mention," said Walden. "Coach Leach had several situations where he punted and didn't go for it ... I felt very comfortable with what he was doing with the play calling, he never once put them in a bad position, he resisted the temptation to take the chance and that's hard to do. I know, I used to slap myself up the head after making a mistake.
"And defensively, wow, they did everything as well as you could do it. I never had a moment where I wasn't comfortable with what they were doing ... There were no mistakes being made because the coaches and the players were on the same page."
The Cougar d-line was critical to the victory, he said.
"It doesn't do you any good if you're great in the secondary if you don't have a great defensive line and WSU really did well there against USC," Walden said. "And what makes a great defensive back is a good front. Yes, USC had a good little drive here and there but it led to nothing.
"They're getting linebacker play, too. And the secondary is experienced except Daquawn Brown and he did some good things too. But the linebackers are playing good, the defensive front is really playing well."
OTHER WALDEN OBSERVATIONS:
"That was a great individual job by the receiver (Dominique Williams), he did a good job maintaining his balance and making USC miss two tackles. That's all you can do in that situation, you can't throw the ball deep at that point because you just don't have the time."
"I got a lot of flak for saying that, everyone thought I was crazy but when you get down to 60 scholarship guys, you just don't have the depth and that hurts you in practice too," he said. "That's what sanctions do to you and Washington State took full advantage. USC still has a great defensive line and an above-average defense but I knew this was coming and it's only going to get worse."