My impression with religiously-motivated Muslim attacks is that they kill every single person who remotely looks like an infidel. They carjacked some guy and let him walk away. Never mind religious reasons - for operational ones, they had every reason to kill him and stuff his body in the trunk (or bury it somewhere where it wasn't likely to be found any time soon). But they let him live.
The carjack victim’s name is Tarek Ahmed. Sounds muslim to me. Sometimes they don’t kill muslims like the Afghans who murdered 10 Christian international humanitarian aid workers / volunteers, but spared their muslim Afghani driver.