Yes very very closer but not the same :)
In the file linked...
There are one big curve "curve", a little curve "straight" near the extremity and "on" it, a big curve "straight" tangente to the little curve
I had no preconceived ideas of that, now I am fixed :)
That maybe good to know that in particular extrem conditions :)
So it's better to draw out a curve "curve" by the function "Extend" than by an tangent aligment to the control's points :)

So MoI is a very cool tool for verify geometry concepts :)

Ps Is it possible to have somewhere the Zoom status? (with some decimal numbers :)
I have made that : a curve extend to a line, and an extension by the alignment of the control point (see divergence jpg)
I made some mouse's wheel actions before see a "divergence" :)
What is the "clickety clack zoom dimension" of a wheel action?
I made as an approximation of 125 "single" clikety clack :)

PSs Have you plan an "intersection Snap On" with a surface when you start a line ?