Two fair questions for Seattle's Pete Carroll

Two questions for Seattle Seahawks coach Pete Carroll following a 28-24 defeat at Detroit in Week 8:

What is his team's defensive identity?

Seattle might have figured zone defense was the best way to limit Lions receiver Calvin Johnson. From that standpoint, the strategy arguably worked. But the Seahawks don't look comfortable playing this sit-back-and-wait style. They've got big, sticky cornerbacks. They've got athletic safeties. They're equipped to play defense on their terms.

Too many times, however, the team seems to be sitting back in critical situations.

This approach seemed to be what happened in Week 1 when Kevin Kolb suddenly checked into the game at quarterback for Arizona. Kolb led the winning touchdown drive in the fourth quarter.

This seemed to be the approach for long stretches against Tom Brady and New England (though not so much in the critical moments, when Seattle's defense made game-winning plays). The Seahawks, playing at home, managed to win anyway on a last-second pass.

And the conservative approach was certainly in play against Detroit, including when Johnson got open for what easily could have become the winning touchdown pass.

Johnson could not quite handle that ball. His quarterback, Matthew Stafford, admitted he threw it with additional velocity because he feared the Seahawks' length in the secondary. Teams will fear that secondary less if the Seahawks abandon what they do best, which is to agitate receivers with constant pressure.

I've been conditioned to avoid scheme-related criticisms because they're often made too easily without consideration for all the factors a coach must weigh with a game in the balance. Some of those factors wouldn't even occur to those of us watching from the outside. I'm no coach and couldn't explain the nuances of an NFL defense. That is why I'd like Carroll to explain what's going on.

Does Carroll chart the defensive performance by coverage across similar situations? What does the evidence say?

These are not new questions.

Former NFL assistant Rick Venturi, now an analyst for 101ESPN St. Louis, brought up the subject after Seattle lost to the Rams in Week 4.

"[Pete Carroll] ought to press every single down man to man," Venturi said then. "If he were standing here, I would say it to him. Every time he plays zone defense, he gives you a chance to throw the ball."

What's up with that challenge?

This question is more rhetorical in nature. Certainly Carroll could not justify his decision to challenge a third-and-8 pass completion with 6:38 remaining in the third quarter. Could he?

Officials flagged cornerback Brandon Browner for defensive holding on the play. Detroit declined the penalty, preferring instead to take the 9-yard completed pass from Stafford to Titus Young.

The penalty would have resulted in an automatic first down, if accepted.

Carroll threw his challenge flag anyway. Officials upheld the ruling. Seattle lost its first timeout of the second half in a game it led, 17-14.

Seattle finished the game with two timeouts to spare, so the ruling didn't come into play. It's one we need to set aside for future reference. Coaches are going to make mistakes, but alarm bells should sound when they err so obviously.

Perhaps there was an error of administration or some other explanation. I'd like to hear it.

Update: Carroll said on 710ESPN Seattle that he suffered from a "crazed moment" on the sideline. The play clock was running low. Coaches were telling him the pass was incomplete. Carroll said he challenged the call as a competitive reaction in the heat of the moment. We'll revisit this subject if Carroll suffers from a similar lapse and it costs the team.