There are numerous faults that could possibly be found in a wine. The only way that you can tell is through smelling or tasting the wine – outside of oxidation, which is also a visible fault.
Every year there are less faults found in wines as wineries around the globe are becoming more careful of cleanliness in the winery, and winemaking is becoming ever more technical allowing for less human error. This may sound like the winemakers are becoming removed from the ‘natural’ product that is wine. Yet we see it as a good thing as the last thing you want is to spend XYZ on a bottle of wine for a special occasion just to find it is reductive or has cork taint.