I see two sides to this: on one hand, gathering opinions on a problem / question is good thing because it means multiple brains on the problem, multiple points of view and schools of thought, crazy ideas that might be the trigger for a super idea, ideas feeding off of other ideas. On the other hand, he could be fishing for answers that validate his answer, which means he is actively feeding a bias we all tend to have. This, of course, would be not a great way to operate for himself. If you are just noticing this with you, it could also mean he is telling you he doesn't trust you.
I don't know that you want to tell him the information you provided is enough if my first thought is true. You'd instead want to exploit it even if it makes you feel insecure as a manager. It might be worth a general inquiry to him about his method. Let him know you observed this behavior and simply ask why. Uncover more information before you judge what is going on.
And also take a look at yourself as a manager. Managing others can often times make a manager, especially new one, feel very insecure.