Uhmmmm...
I can only think of two explainations... Electronic failure of some kind or a mysterious disapearance of all your fuel for a minute while you ran on fumes and then it was replaced.
Which do you feel is more likely?
Where was the needle originally? Were you going up or down a steep grade? If the fuel meter thingy in the gas tank gets the impression that your fuel is low because of gravity then it can move about a bit. If you were on a flat stretch of road and it just dipped and spiked again then I'd say you had a relay go out or something like that. I don't know if your gas meter has relays, but some kind of electric problem occured. Does your needle go all the way to 'empty' when you shut off the engine normally? Maybe its just the fuel meter that is on the fritz. I think it was the disapearing gas theory.
Did you check the 
Linear Mode
