It dosn't matter if it was "only a bit" or whatever. If he'd pee or take a dump on a player, sure he wouldn't have caught rabies, but it is still not legal to do it on, off, below, above, outside, or especially on the pitch. It kicking someone is also a very, very serious offence, but it COULD be more difficult to judge it you kick a player accidentially or by intent since you quite often use your feet to kick the ball as a vital aspect of the game. Your teeth on the other hand is rarely anything you should, or want to use when playing football.
That said, I despise players who kick others for the heck of it, but the issue here is that we all assumed LS would not repeat this, the same stupidity yet again. Not to mention that he didn't exactly promote fair play in his last WC either... Something which I believe is an important aspect, not only towards LS, but hellofa lot of players these days. To be completely honest, players these days play so unfair and rotten that they should have their whole body covered with something covering, and fingers constricted so that it would be impossible to hold others as well, then perhaps we would see some proper fair play, right?