> Anyone else do something similar? How did you recover?

Very human situation -- turns out that interviews and auditioning aren't always the ideal environment to evaluate talent. There's still time to salvage the situation.

Send the hiring executive a note today-- be candid "I totally choked, would you be amenable to a do-over? I'd like to show you that I really know my stuff."

Personal disclosure, learning, and good humor are desirable team member qualities. The worst they can do is say no.