"Let me say this ... I know this: I couldn't be more disappointed," Jones said Tuesday morning on KRLD-FM. "Frankly, I'm surprised we didn't play better."
Jones watched quarterback Tony Romo tie a career high with five interceptions. And the offense gained only 41 rushing yards.
"They took care of the ball. They made plays with the ball. We didn't," Jones said. "We got beat soundly. That's all there is to it."
"You have to get over it," Romo said Monday night. "It's going to suck for a few days now. Obviously it's going to sit there in your stomach and just eat at you. ... I can't try to do too much. I think I tried to do that too much. Going forward, I'm just going to have to do my job. And I will."
Despite a career-high 105 receiving yards, wide receiver Dez Bryant dropped two passes and misread a defensive coverage, which led to an interception returned for a touchdown.
"Very, very, very, very, very, very average," Bryant said. "Yeah, I felt like, me personally, I could have played better. ... (I've) just got to keep fighting through adversity."
The defense struggled to bring down Bears quarterback Jay Cutler, recording two sacks. Chicago receiver Brandon Marshall had seven catches for 138 yards with one touchdown. Matt Forte, playing with a sprained ankle, rushed for 52 yards on 13 carries.
"I'm disappointed and frustrated we didn't execute better," tight end Jason Witten said. "We knew the style of defense they would play. You can't turn the ball over and win in this league. We know the stats."
Jones said center Phil Costa, who has been out with a back injury since Week 1, could return after the bye week. Two other starters -- nose tackle Jay Ratliff (ankle) and defensive end Kenyon Coleman (knee) -- also might be available against the Baltimore Ravens on Oct. 14.
After scoring 24 points in the season-opening victory against the New York Giants, the Cowboys have scored just 28 points in the last 12 quarters.
"We all see what happens when your quarterback tries to do too much," Jones said.