I would not be all all surprised that the author just made stuff up, or included it because he saw it someplace. If it does not have references, it is not a academic work, and should not be taken too seriously. A lot of stuff is going to be myth anyway.
The primary sources for the life of Siddhārtha Gautama are a variety of different, and sometimes conflicting, traditional biographies. These include the Buddhacarita, Lalitavistara Sūtra, Mahāvastu, and the Nidānakathā. (wikipedia)
So, does anyone know what the best academic work is comparing source materials on the life of Buddha? Something that is the quality of Analayo's satipatthana? I'd read that, but admit, otherwise I don't really care much beyond a sketch.http://www.accesstoinsight.org/ptf/buddha.html
Anybody read these?For more thorough accounts of the Buddha's life, please see these two excellent anthologies: The Splendour of Enlightenment: A Life of the Buddha (two volumes), compiled by Phra Khantipalo (Bangkok: Mahamakut Rajavidyalaya Press, 1976), and The Life of the Buddha by Bhikkhu Ñanamoli (Kandy: Buddhist Publication Society, 1992).