yes you can flood an EFI car. hold the throttle at WOT and then try and start the car.. ECU is gonna see the WOT and dump more gas then a starting car knows with to do with.

the difference is.. you can't flood the car, until you try and start it. But you can flood it while trying to start it.

but yeah.. with that being said.. My guess is that the throttle got stuck.. and now that it started and idle'd fine.. it might have poped back to normal.. whatever was stuck in the throttle system that is.