It seems that the line indicator "understands" the change of line only whether the enter button is pressed.
To be more specific, if i type some text and it reaches the EOL and i continue typing in the next line, whithout the enter usage but with the default line change of the editor, the line indicator at the bottom of the application doesn't realizes the line change and as a result it still indicates that i am typing on the first line.
The line indicator actually only shows newlines (ie hard returns) since these remain constant, whereas the window can be resized to fit the text into different numbers of lines on screen.
This may be a bit unintuitive, though, and I wonder if it would be useful to have an option where text only fits within a certain width and shows the number of lines on screen within that area. That would help with the also unintuitive printer layout or for limiting the space of text.
In addition, i can see that the line indicator is not working at all when it comes to HTML or RTF view.