bug with linear_least_squares_fitting_3()?

lsfit.cpp

// Example program for the linear_least_square_fitting function
// on a set of 3D triangles
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/linear_least_squares_fitting_3.h>
#include <vector>
#include <math.h>

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;

typedef K::Plane_3                  Plane;
typedef K::Point_3                  Point3;


int main(void)
{
  std::vector< Point3 > lsPts;
  Point3 a(318.60, 919.16, 211.76);
  Point3 b(317.60, 915.36, 208.79);
  Point3 c(456.88, 878.84, 208.65);
  Point3 d(458.14, 878.52, 208.65);
  Point3 e(459.11, 882.25, 211.58);
  lsPts.push_back(a);
  lsPts.push_back(b);
  lsPts.push_back(c);
  lsPts.push_back(d);
  lsPts.push_back(e);

  std::cout << "collinear= " << CGAL::collinear(a, b, c) << std::endl;

  //-- 1. plane thru first 3 points
  Plane p1(a, b, c);
  // std::cout << std::fixed << std::setprecision(3);
  // std::cout << a << std::endl;
  std::cout << "plane= " << p1 << std::endl;
  for (auto& pt : lsPts) {
    double dist = CGAL::squared_distance(pt, p1);
    std::cout << "dist= " << sqrt(dist) << std::endl;
  }

  //-- 2. least-square plane
  Plane plane;
  linear_least_squares_fitting_3(lsPts.begin(), lsPts.end(), plane, CGAL::Dimension_tag<0>());  
  std::cout << "lq-plane= " << plane << std::endl;
  for (auto& pt : lsPts) {
    double dist = CGAL::squared_distance(pt, plane);
    std::cout << "dist= " << sqrt(dist) << std::endl;
  }
  
  //-- 3. least-square plane with only 3 points
  linear_least_squares_fitting_3(lsPts.begin(), lsPts.begin()+3, plane, CGAL::Dimension_tag<0>());  
  std::cout << "lq-plane-3-pts= " << plane << std::endl;
  for (auto& pt : lsPts) {
    double dist = CGAL::squared_distance(pt, plane);
    std::cout << "dist= " << sqrt(dist) << std::endl;
  }

  
  std::cout << "==========" << std::endl;


  
  return 0;
}