PVS-Studio warning V535 for Doom3

bool idMatX::IsOrthonormal( const float epsilon ) const {
  ...
  for ( int i = 0; i < numRows; i++ ) {
    ...
    for ( i = 1; i < numRows; i++ ) {
      ...
    }
    if ( idMath::Fabs( sum ) > epsilon ) {
      return false;
    }
  }
  return true;
}

This suspicious code was found in Doom3 project by PVS-Studio static code analyzer.
Warning message is:
V535 The variable 'i' is being used for this loop and for the outer loop. idLib matrix.cpp 3128

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