If someone switched flaps up instead of gear up, it would not be something as simple as wrong switch. But both operations (gear up and flaps up) are part of the normal procedures after takeoff, so it is conceivable that a flustered pilot could be mentally at the wrong place in the checklist, but this seems unlikely unless something else had really gone wrong.
(I am not sure of the normal procedure for this plane, but typically gear up is as soon as the plane is airborne and you have a stable climb, and flaps will be retracted , usually in stages, as airspeed increases, but this is very dependent on the aircraft and the airport and company procedures.)
