Had the ball gone straight in, without entering play, the correct decision is no goal and the ref awards a corner. Same if a GK takes a goal kick and it goes straight into his (or her) own net. Saw this nearly happen when reffing straight after the October 87 Great Storm. A GK took the kick, the ball went up into the air and the wind took it back and just over the bar. Same applies from a throw in if it goes straight in the net without touching the ground or a player.