As far as his race/ethnicity, his father was Filipino & his mother Italian:
"...described himself on social media as being affiliated with the Seminole Warriors boxing club. However, his cousin {Lenny Altieri} said Sayoc’s mother was Italian and his biological father was Filipino, and his parents separated when he was a young boy. Altieri said the only connection to Native Americans was that Sayoc a decade and a half ago had dated a woman in Minnesota who was a member of a tribe."
That seems to be sufficient for the press generally to call him a Native American. Why they would do that I don't know unless Indians have been trending Republican in their voting habits.