Yeah, East Asian is a term for lack of a better one, meaning Japanese, Chinese, Korean, etc. Obviously, as races are not really so distinct, it gets messy with Southeast Asian nationalities. Vietnamese, Singaporian, Thai Cambodian, and whoever else may fall into the general grouping based on looks. I understand the author's intent, and wouldn't make much of it.
There are south Asians (Indian, Pakistani, Bangladeshi, etc.), West Asians are sometimes called Ural-Asians, and often just lumped together with Europeans, meaning Russians, Ukranians, Georgians, etc. Some people refer to folks like Mongolians, Kazakhs, etc. as being central Asian.