What about if you have an unemotional role-player in a group and nothing excites him. His character almost dies and his character discovering a vault of treasure is like the same event. Is that how some people are or would you say he is bored?
What about it? Some people aren't expressive but inside of them they are very happy or very content. Have you ever chose to ask them if they are enjoying the game or what they think about just happened?
True, Pathfinder.
I pose another answer to your question, Hunter. Some individuals are delayed responders. These are the kind of people that are stones during the event but days and weeks later are so animated about the event that you wonder which side of them was really at the table during the game.
I am actually one of those kinds of people. When something happens, I choose to keep a 'cool head' and not show too much excitement or disappointment (My family hates that at Christmas). But I am not bored or dissatisfied in any way. If I wanted something different, I would usually say so later on, after 'cooling off'. The best way to find out is to do as Malcolmshaw said and ask. He should be able to tell you if he likes your game or not without it being a big deal.
First of all, I applaud these kinds of new Topics where the thinking is outside the box and the awareness above just system rules and how to swing a sword.