You're wrong. The 10-k would be due today. It's due no more than 30 days after the extension is filed. The link below is a securities' lawyer's website.
"For example, if an issuer’s 1934 Act filing delinquency is due to a late annual report on Form 10-KSB, the issuer can file a “Notification of Late Filing” on Form 12b-25 and receive a 15 day filing extension. If for somereason the issuer fails to file its Form 10-KSB during the 15 day filing extension, the issuer should still be within the OTCBB grace period and should therefore have up to 15 additional days to bring its filing current"