If it's not Rule #1 in elementary appellate procedure, probably it should be - don't lie on your certificate that your brief complies with applicable length limitations - at least where it flagrantly violates those limits. Chances are your opponent can count, since s/he did graduate from law school, and going to law school does not extirpate all normal education.
And if you violate Rule #1, remember Rule #2 - pray that you don't get Judge Posner on your panel
In Abner v. Scott Memorial Hospital, ___ F.3d ___, No 10-2713, slip op. (7th Cir. March 9, 2011), the plaintiff appellant violated both of these rules. Plaintiff filed a brief that was over 18,000 words long, but claimed in her certification that it was only 13,877 words long. Id. at 2. Sure enough, the defendant could count and dropped a footnote to that effect.
Judge Posner read it and sua sponte issued an order to show cause why the false certification should not be sanctioned. The rather lame excuse, coming only after the order issued: that counsel had "inadvertently" thought that only the argument counted against the word count. Slip op. at 3. Oh, really? Assuming that's true - which the court did not - (id. ("It is difficult to see how these errors could be 'inadvertant'.")), an appropriate sanction would have been to require to read the entire appellate rules aloud, into a dictaphone, and send the tape to the court for verification.
Judge Posner didn't do that, although it did point out (correctly) that it's right there in the rules. Slip op. at 3 ("There is no ambiguity, hence no room for misinterpreting the rule as confining the required word count to the argument portion of the brief").
Apparently this lawyer didn't read the briefs anymore than he read the rules. Having neither facts nor law to rely upon, he started pounding the table. He tried to blame the other side for some sort of "ex parte" contact with the clerk's office, slip op. at 4, when in fact it was the opposition's footnote that caught the court's eye. So counsel ended up not only wrong, but loud wrong.
Instead Judge Posner apparently became the first appellate judge in history to summarily affirm on the basis that the appellant violated the word count limits. See Slip op. at 5 ("We haven’t found any cases in which a court dismissed an appeal for violation of Rule 32 alone."). Sure, he added a boilerplate paragraph at the end the the appeal was also substantively meritless, id. at 6, but it was appellant's brazen, remorseless (the court itself labeled it "flagrant," id.) violation of the word count that brought about the six-page, published summary dismissal.
Whoever said there's nothing new under the sun (it's biblical) didn't know any lawyers.