The whole argument rests on chapter d:
(d) Each assignment under paragraph (b) of this section must provide for at least 10 consecutive hours of rest during the 24-hour period that precedes the planned completion time of the assignment.
This says it all--planned completion.
Agree with you and YIP....our FSDO which is different than YIP's interprets it the same way.
Like someone mentioned....if something happens after the 14 hours they'll get you for careless and reckless however.