I agree that some bad advice can be given even by LEO or Military/Ex-Military guys. There are plenty of LEO's who don't even know some of their local laws or don't shoot as much as civilian firearm enthusiasts do.
Their experience and background is always good, but it takes more than that to be proficient and knowledgable with firearms. Continuing training and education is important too, along with lots of practice.
I have a good friend who is a Veteran Marine and is now a Deputy. Everytime I go to the range and invite him to go, he usually turns me down even if he gets a discount or shoot for free because he's a LEO. And he's not even up to date with my state's CCW laws as much as I am, and hes a cop!