Actually it’s looking less and less like that.
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 other issue is that a jihadi looking to slaughter infidels would have amassed a much higher body count simply going door-to-door and killing everyone in his path. In Bombay, that's exactly what they did, with 11 guys amassing a body count of 160+ victims.