Fireball and line of effect (avoiding creatures)

[Baka_Dwarf]

We had a discussion about the description of how Fireball works when you have creatures in the way between the caster and the point where it want to detonate.

We had in line a Caster (C), te Fireball Spell (X), a Fighter (F) and an Air elemental (AE).

The caster targted the point behind the Elemental, the dungeon master sayd he can't because it detonates when it hit the first body or barrier as the Fireball text say's. But the same text let you target across a small hole if you use a ranged touch attack. A character (player or monster) use a square to fight in combat, but that not means the WHOLE square is full, it means you can even "squish" or use acrobatics to pass through it in combat. But the DM don't let the Caster to cast and target the Fireball through it. At the end of discussion we had it:

(C)___(F)_(AE)__(X) [caster 15 ft away from fighter<5 open between> Elemental and the designed point to detonate 15ft behind the target (the elemental).
Resulting in:
(C)__(X)(F)_(AE) [The Fireball hit the fighter, first "material body" in the way and it detonates causing damage to ALL in the effect area.

The discussion become weird because everytime the game says a character is targeted it means "CREATURE", but the DM sayd "material body" is the same thing while we stand this means a large object like a barrel or a dresser.

The main question is: There's a way to avoid a character, (player or monster) and hit the target (point of detonation) behind, avoiding it as the same rule of "narrow passages" or a 5,7f height character for rules will not let a small pea-sized spark cross through it?

Thanks for read.

[Java Man]

Compare the penalties for firing an arrow through an arrow slit or past a creature. The arrow slit penalty is double the creature. Now, we have a specific mechanic for firing a firebal through an arrow slit, logically getting it past a creature should be easier. Easier than a touch attack sounds automatic to me.

Or, try this, the rules say there is a penalty for X, but not Y, your GM is just nerfing the spell if he invents a penalty for Y.

[Chess Pwn]

yeah, your GM just doesn't want it to work. You can target a corner of an empty square if you wanted, and you're free to shoot it past enemies per the rules.

One thing you can try is doing it above the enemy, that way it explodes down to only hit them.