The part where they state that:
a = Det[bigMatrix];
b = Det[bigMatrix];
give different results is solved in my version of Mathematica (10.0.1.0).
Try e.g.:
basicMatrix=Table[Table[RandomInteger[{-99,99}],{i,1,14}],{j,1,14}];
powersMatrix=DiagonalMatrix[10^{123,152,185,220,397,449,503,563,979,1059,1143,1229,1319,1412}];
smallMatrix=Table[Table[RandomInteger[{-999,999}],{i,1,14}],{j,1,14}];
bigMatrix=basicMatrix.powersMatrix+smallMatrix;
Do[
  a=Det[bigMatrix];
  b=Det[bigMatrix];
  Print[a==b]
,
  {10}
]