Athene did not receive the realm first achievement because he transferred to a new server, and its right in the server transfer FAQ that you are ineligible for realm first achievements until after 60 days. Think his video showed him hitting 85 in about 5 hours tagging, while the achievement went out at 14 hours, Athene was nearly 3 times faster.

The question here is about Refer a Friend, not server transfer. So blue posts about Athene probably wont help us find out about RaF.