Most policemen or firemen I’ve known are very stubborn. Some would call it strong willed. Most also have a definite sense of what society defines as right and wrong.
Nothing bad there. Firemen go into FIRE to save people. Police face gun-wielding criminals to save people. Both are heroes to me.
Besides, if the issue is THAT important then they SHOULD be stubborn. If it's not important then USUALLY a bribe, like a piece of chocolate cake, can sway the more stubborn.