I have to laugh at the whole "they didn't cry, so they aren't grieving and so, therefore, it's all fake". Give me a break.
I was 19 when my Mom died. The day my Mom passed away, I didn't break down and cry immediately. Actually, I forced myself to cry (and felt fake/embarassed doing so) because I felt like it was something I needed to do, but I felt nothing. My mind was in shock. I was completely numb. The night of my Mom's death, the family sat around and laughed and told stories. We watched a movie and ordered Chinese. The next day, my Dad, sisters and I went shopping (for funeral attire) and out to eat and had a nice time together. We didn't cry when we were together. My friends would call me and offer sympathy for my loss and I was like "Oh, no. It's okay, really" -- like I had just lost a goldfish, and not a parent. My sisters and I worked on a collage for her memorial service and we laughed and joked around while we looked at pictures. I didn't cry. The day of her funeral, I didn't cry. I needed to. But, in a way, I held it in and instead, I smiled. A few days after her funeral, it all hit me at once and I spent the next couple of weeks/month or two crying every night in bed over her loss.
That is how I grieved. My mind had a hard time processing the fact that my Mom had died. I didn't believe it. I knew my Mom was gone, but deep down I kept telling myself "Nope, she'll just walk in the door or call me and this will have been nothing but a nightmare."
Not everyone grieves the same and it's very easy to say "If I lost so and so, I'd be crying non-stop" or assume everyone functions that way. I've seen the video of Emilie Parker's Dad "getting into character" and pretending to be sad talking to the press. I genuinely believe he was sad. Personally, I feel like he was just mentally preparing himself to talk about his daughter and taking deep breaths. Weeks after my Mom died, it was easy for me to have a casual conversation with someone and smile, but the minute someone brought up my Mom, I had to take a second to compose myself. My whole demeanor, tone would change. It's normal.