It reminds me of a point from non-Euclidean geometry. In Euclidean geometry a triangle has 180 degrees, but in hyperbolic or elliptic geometry it has more or less (I forget which way). So you could start measuring triangles to find out whether our universe is Euclidean or not. But since every measurement has an error interval, e.g. 180 +/- 0.000001 degrees, you may some day prove the universe is non-Euclidean, but you could never prove it is Euclidean! It may be "skewed", but just less skewed than your instruments can measure.