Why is it an un-Islamic sentence? Because al-Badawi (who is not the [1] Islamic apologist who owes me a million bucks) no doubt thinks that a Muslim court should support his jihad activity, and not hinder it. From "Yemen upholds 1 death verdict in USS Cole blast," [2] MSNBC, with thanks to TS:

SAN’A, Yemen - A Yemeni appeals court on Saturday upheld the death sentence against a militant convicted in the 2000 al-Qaida bombing of the USS Cole and reduced a death sentence to 15 years in prison against another defendant.

The death sentence was upheld against Abd al-Rahim al-Nashiri, a Saudi suspected of being an associate of Osama bin Laden.

The court overturned a death sentence against Yemeni militant Jamal al-Badawi, sentencing him instead to 15 years in jail.

“This is an un-Islamic and illegal sentence,” al-Badawi shouted from inside the defendant’s cage.