This happened to some bike club friends a few years ago - a Lightspeed got pretty badly damaged that way. I would be terrified to have a roof rack b/c I just know I would do the same thing! (Of course, I no longer have a garage, so it's a moot point now.)
One tip I read to avoid this is to put the garage door opener in the bicycle seat bag on the rear rack, forcing you to stop the car and get the bike down before you can open the garage door.
Hope there's not too much damage to your Kona and that it's easily and inexpensively repaired. It's always something, isn't it?!
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow