Yes it would be if you deliberately left the game however you said it wasn't deliberate. If you were in roleplay with somebody, send them a message stating that your PC crashed etc and that you will continue the roleplay when you get back on if they wish or alternately contact an admin on teamspeak stating that your PC crashed and it wasn't a deliberate combat log so if you did get banned for it, you have evidence that you have explained your situation to an admin. Would like to add that you must respawn before logging out intentionally as that would be combat logging.