Luckily I was there to help him as it happened. I quickly turned it off, turned it upside down and gently shook it (no spinning HD) to help the liquid pour it (it did). I then rest it upside down, screen open hanging off the edge, with the body of the mac on a towel on a bed (keep letting it drain. Quickly I removed the underside to examine the damage ... but too my surprise I saw no liquid whatsoever. I have a feeling he may have lucked out, so I powered it on with the battery out just for a minute to see what worked/what didn't. Everything works, trackpad, keyboard, all hardware checks in fine. So is it necessary I keep it off?