And it was the most crucial one, at that.
Ryan's pick-six to Carolina Panthers veteran Drayton Florence left some wondering if Ryan just made another poor throw or if inexperienced receiver Drew Davis ran a poor route. Koetter provided clarity on the matter.
"They fooled us on the coverage," Koetter said of the Panthers. "They were showing us a single-high look. They were showing us a single-high look from the [coaching] box. I thought it was single-high look. We thought we had Drew Davis one-on-one over there on [Florence]. They were giving us a blitz from the other side.
"They did a great job of disguising it. It was actually a trap coverage. So Drayton did not have to back up. The safety who was down all the way over Tony [Gonzalez] backed up, so Drayton knew he had help. He didn't have to back up. We had a hitch route over there. He sat on it. Right as it's coming out of Matt's hands, he realizes what's happening. He tries to bring Drew back, and it was just a bad timing on the play. ... They were in the perfect [coverage], and it fooled us. It happens."
Fooled or not, the Falcons have to find a way to cut down on the turnovers. Ryan has seven interceptions over the past two games. And the next team on the schedule -- Seattle -- doesn't necessarily need deception to wreak havoc with its opponent. The Seahawks are rather solid at just lining up, man to man, and dominating behind a strong defensive front, arguably the NFL's best cornerback in Richard Sherman and arguably the NFL's best safety in Earl Thomas. Sherman and Thomas each have four interceptions, which is tied for the league lead.
Thomas picked off Ryan in the fourth quarter of last season's NFC divisional playoff game, leading to a Seattle score and giving the Seahawks momentum to take the lead before the Falcons scratched out a 30-28 last-second, come-from-behind win.
"That guy's spectacular," Koetter said of Thomas. "He's playing as good as anybody in this league right now. ... Unbelievable range. Explosive tackler. Big hitter. Good ball skills. You know, just a top-notch player."
The Seahawks are tied for seventh in the league with a plus-six turnover ratio, including a league-leading 13 interceptions. Conversely, the Falcons are tied for 26th with a minus-seven turnover ratio.
"As a defense, Seattle does a nice job with takeaways," Koetter said. "We'll definitely have to be on our best to not turn it over. Coach [Mike] Smith has three musts every week, and that will be one of our musts. So, we can't turn the ball over against these guys.
"We've got to eliminate turnovers. As soon as we do that, everybody will be happy with Matt again. The quarterback gets all the blame when things go wrong. He gets a lot of credit when things go right."