I feel Toby Hosking is not convincing

Toby Hosking as Second Assistant Director in Shaun of the Dead (2004) made me pay attention more than I expected. Many moments pass very fast, and I do not remember much after them. The role needs more detail, but the performance stays on the surface. For me, it does not feel very real in many scenes. Some emotions are too simple, and I cannot believe the character enough. I do not hate it, but it did not pull me into the story. Maybe other people will like it more, but this is my feeling.