Complex sentence: The Jordanian government now claims that al-Kasabeh was executed on January 3 rather than February 3 which if it turns out to be correct it would have rendered ISIL incapable of trading him alive for the female bomber, Sajida al-Rishawi.
Split into simpler sentences: The Jordanian government now claims that al-Kasabeh was executed on January 3 rather than February 3. If the previous turns out to be correct it will render ISIL as having been incapable of being been able to have swapped him alive for the female bomber, Sajida al-Rishawi.