Possibly in the cider, although I would expect a little sediment to drop out anyway. If it hadn't properly finished, then it was probably a good thing you poured the bottles away - if you had put them somewhere warm, it could have re-started the yeast and you might have got bottle bombs!
A sour wine is either just very dry (which means it's fermented right out) or infected - storing it in the cold won't cause it to go sour. The WOW (Wurzel's Orange Wine) wines that I have done often taste quite harsh when bottling, but mellow nicely after about three months. They are still dry, as I don't sweeten them with Splenda or the like, but they lose the harsh acidic and vodka-y taste and smell once matured.