"somehow" you bumped the shifter linkage out of adjustment.... if the wheels are moving, it's not in neutral. Will the wheels stop turning if you put the shifter between gears....a little more forward or a little more back?

70 Roadrunner convt. street car 440+6, NOS, 4-spd, SS springs '96 Mustang GT convt. street car '04 4.6 SOHC, NOS, auto, lowered "Officer, that button is for short on-ramps"