He was always considered a band member BUT with Crowded House it takes awhile to earn your stripes *GRIN*. If the album with Peter Jones on drums would of been released I'd say it would of been more "official" for whatever that is worth.
"Hired hand" is so throw away and doesn't do anyone that has played with the band justice.
When someone puts in 100% on their instrument and committed to the gig I believe they are a band member. The music counts above pretty much everything else.