are you sure it wasn't a fruit fly? those things are vectors of infection.
how could it make vinegar that quickly? i though it took a LOT of time and oxygen to produce vinegar.
if you don't need to use that fermenter for a long time, i say let it sit for a year and see what happens. i LOVE sour beer, especially flemish reds with lots of vinegar.
the only issue is that wild yeast and infections will ferment sugar that is not fermentable by "clean" yeast. if you bottle now you may create bottle bombs since the wild yeast continues to ferment for a long time at a slow rate.