Octave fminunc doesn't update - octave

Question

I have the following octave script:
clear;
T0 = [...
1.0, 1.0, 5.0; ...
1.0, 2.0, 3.0; ...
-1.0,0.0, 6.0];
option = optimset('Display','Iter','GradObj','on','MaxIter','300','TolFun',10-5);
[t f] = fminunc(#flatTriangle,T0(:),option);
t = reshape(t,3,3);
And following octave functions
function [cost grad] = flatTriangle(T)
T = reshape(T,3,3);
Q = T(1,:)';
P = T(2,:)';
R = T(3,:)';
e3 = [0;0;1];
nf = cross(R - Q,P - Q);
cost = 0.5*(e3'*nf - norm(nf))^2;
grad = zeros(9,1);
commonStuff = (e3'*nf - norm(nf))*(e3 - nf/norm(nf))';
grad(1:3) = (commonStuff*skew(P - R)')';
grad(4:6) = (commonStuff*skew(R - Q)')';
grad(7:9) = (commonStuff*skew(Q - P)')';
endfunction
function Vhat = skew(V)
Vhat = [...
0.0 -V(3) V(2); ...
V(3) 0.0 -V(1); ...
-V(2) V(1) 0.0];
endfunction
Now despite the fact the grad vector isn't 0 the final output doesn't change at all from the initial input.
Am I using incorrectly something? maybe I'm not configuring something properly?
The code runs but it doesn't seem to do anything.