"Some of the guys were calling 'foul,' so I don't think he knew what the score was," said Singler, who finished with 25 points. "I was shocked."
Washington State players and coaches rallied around Kernich-Drew, saying one mistake did not cause the defeat.
"It was just a mistake," WSU's Brock Motum said. "It's in the past now. He needs to keep his head up."
"If not for him we wouldn't have been in the game," Washington State coach Ken Bone said of Kernich-Drew, who had several key baskets.
Carlos Emory added 20 points for Oregon (21-5, 10-3 Pac-12), which held on to first place in the conference.
Royce Woolridge scored a career-high 36 points for Washington State (11-15, 2-11), losers of six straight. Woolridge missed a half-court shot as time expired.
Washington State built an 18-point lead in the first half, and led by 11 at halftime. But Ducks erased that in the early minutes of the second half.