Drawing line with FlatCap style, Inconsistency in pixel draw if change direction of line

There is inconsistency in pixel drawing if a user draws a line left->right and right->left with CapStyle FlatCap. 

As FlatCap does not cover the endpoints of the line, it works fine for direction left->right, top->bottom, bottom->top. But if user draws a line from right->left, even endpoints are drawn.

I am attaching a sample project stating the problem, you can see that line left->right and right->left has a difference in pixel drawn.