"CRS may also extend crews in the field (up to 48 hours domestic trip and 96 hours on an international trip) to address operational issues, e.g., extending a healthy crew due to another crew "sick in the field" or to recover freight from a broken airplane or for any other operational reasons. These extensions are focused on protecting our delivery commitments to our customers."

Sec 12.A.8.b
b. maintenance or weather disruptions particular to the pilot's specific flight shall, but only to that limited extent, provide the Company with the ability to exceed the 48/96 hour limit without the pilot's consent.

Unfortuntely I learned about this last year