How did Sai Baba's appearance and practices make it impossible to classify him as either Hindu or Muslim?

According to Chapter 7 of the Shri Sai Satcharitra, Sai Baba's identity was intentionally ambiguous. If one considered him a Hindu, he looked like a Yavana (Muslim), yet if called a Yavana, he bore the noble marks of a Hindu. This paradox extended to his practices and residence; he lived in a mosque, a Muslim practice, but kept a sacred fire (Dhuni) burning there day and night, a Hindu tradition. The text further notes that while he was called a Muslim, his ears were pierced like a Hindu, and if called a Hindu, his circumcision was evident. This made his origin and religious affiliation a holy mystery.