Eugene'sOrin's post on disastrous oral arguments (make sure you listen all the way to the end) reminds me of an oral argument that I observed while clerking:
JUDGE: Counsel, your brief does not comply with this Court's rule requiring one-inch page margins.
COUNSEL: Your honor, I believe it does.
JUDGE: I don't think so.
COUNSEL: Your honor, I'm pretty sure it does.
JUDGE (raising hand from bench): Here, I have a ruler--would you like me to measure?
COUNSEL: Um, no honor, that won't be necessary. Uh, could you please just sanction me, not my client?