when "in the spring of 2011 at the age of 25... he and his wife arrived in the United States from his native New Zealand. He enrolled at Golden West Community College".
The evidence is right in the article you linked if you cared to read it for any other reason than to jab BYU:
2011 - JC Freshman
2012- JC Sophmore
2013 -Unsuccessfully tried out for the NFL (used academically as a redshirt year)
2014 - Enrolled at BYU and played rugby (his sister was on the WBB team)
2015 (the year in question) - his perfectly legal senior year where he played rugby again
He wasn't eligible to transfer to a 4 year school for football because of 2 non-academically related club football games he played in 4 years earlier.