A) You never said Lith was stuck in the ground. You said it was being held defensively, which implies a position more or less parallel with the ground, so as to cover as many vital areas as possible and still retain mobility in case of an attack from an unexpected angle.

B) The only part of Lith that has been stated to have a larger than normal surface area would be the head, which wouldn't be anywhere near your face. The rest is assumed to be the width of a standard polearm and the coverage of more or less normal plate armor, since nothing else was specified.

C) As I said before, the bolt was not fired straight. It was fired up, then arced down toward his head. Holding Lith in front of the face would do nothing to impede the attack. He would have to be holding it at an angle above his head, otherwise the bolt wouldn't strike Lith. 

D) He has no reason to suspect the attack would come from above instead of any other direction, so holding it in front of his face (as you said he was doing) would be the most logical position since it provides the best coverage possible. 

5) Even if Lith did manage to be placed in the correct position to intercept the bolt, it still wouldn't be stuck in the ground and the ability to completely negate an attack that has been prepared for three posts with a defense that has been prepared for two is only achievable by a character a tier above the one he's fighting. Unless you're suddenly promoting your character to high tier, you do need to take damage even if the bolt is intercepted by Lith. Not full damage, but not exactly a pittance either. 

6) All of this is assuming that we're using a rule-set similar to the one used in the previous attempts at a multiverse (which I assume we are since we adopted that tier system).

Addendum to B) Upon re-reading the CS, Lith is stated to be an eight foot lance, so we can assume that the dimensions would remain proportional to a standard lance meaning that the thickest point (just in front of the grip) is no more than 6 inches across, not nearly enough to intercept the bolt when held in front of the face. That's also assuming a jousting lance rather than a battle one.

Last edit, I promise. :P I apologize in advance if I start to sound high and mighty or something, and I don't mean any of it like that. I just kind of turn into spock when I go into debate mode.