Depending on when you are interviewed it is possible your squad leader has gotten to know you pretty well so having rehearsed answers is going to sound pretty stupid if that isn't you. They will probably be able to tell if you are just feeding them what they want to hear. On the flip side having your squad leader do it is a good thing to because you have gotten to know them as opposed to your nomination interviews where you will be interviewed by someone you know nothing about (in my case at least). So I wouldn't worry. Going into my interview I feel like my squad officer already had a good idea of what he was going to write down based on what he had seen that week. Just work hard during PT, don't mess around during formation, get everywhere on time, and have try to have fun while being a positive impact on your squad.