The most glaring? What defensive coordinator Sean McDermott calls the four-minute defense.
Carolina had Seattle pinned at the 3-yard line with 4:42 remaining. But on second-and-15 quarterback Russell Wilson was able to connect with running back Derrick Coleman on a short pass that turned into a 12-yard gain because linebacker Jon Beason missed a tackle.
On the next play, Seattle converted for a first down and the Seahawks were able to run out the clock.
The easy explanation for what happened is the Panthers were gassed, but that's just an excuse. Was Beason tired? Well, yes. It was his first full game after missing a year recovering from a knee injury. But again, he'll tell you tired is no excuse.
Were others tired? Yes. The four-man rotation at defensive end was reduced to three when Frank Alexander was ejected for taking a swing at a Seattle lineman after a big sack by safety Charles Godfrey. He'll be fined later in the week, and coach Ron Rivera already has given him an earful for hurting the team.
But again, those are excuses.
"It's unfortunate we played such a good game but we couldn't finish at the end,'' Beason said. "It's a tough pill to swallow.''
Carolina's secondary also gave up too many plays as quarterback Wilson passed for 320 yards, his first 300-yard game, including a game-winning 43-yard touchdown pass over cornerback Josh Thomas.
As well as Thomas played against the run, look for Carolina to use Josh Norman more this week against Buffalo.
But there were far more positives than negatives. The Panthers held running back Marshawn Lynch to 43 yards on 17 carries and the Seahawks had only 70 total rushing yards. They sacked the elusive Wilson two times and pressured him countless others without using a lot of exotic blitzes.
As fellow ESPN NFL Nation colleague Terry Blount said after watching the stout Seattle defense all preseason, "The Panthers' front seven is really good.''
"Probably as good as I've been around,'' said McDermott, who was involved with some pretty good defenses at Philadelphia. "They're not there yet, but probably as good as I've been around.
"Now that people have seen how good they can be, how disruptive they can be -- I'll give you another word for potential, because I don't like that word -- [but] they have a chance to be pretty darn good.''
But there is room for improvement.