Can I cast the spell of a spell storing melee weapon thrown?

Question

Spell storing is a Magic Weapon Special Ability which can only be placed on melee weapons:

A spell storing weapon allows a spellcaster to store a single targeted spell of up to 3rd level in the weapon. (The spell must have a casting time of 1 standard action.) Anytime the weapon strikes a creature and the creature takes damage from it, the weapon can immediately cast the spell on that creature as a free action if the wielder desires. (This special ability is an exception to the general rule that casting a spell from an item takes at least as long as casting that spell normally.) Once the spell has been cast from the weapon, a spellcaster can cast any other targeted spell of up to 3rd level into it. The weapon magically imparts to the wielder the name of the spell currently stored within it. A randomly rolled spell storing weapon has a 50% chance of having a spell stored in it already. This special ability can only be placed on melee weapons.

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Some melee weapon can be thrown:

Melee weapons are used for making melee attacks, though some of them can be thrown as well. Ranged weapons are thrown weapons or projectile weapons that are not effective in melee.

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A dagger is a melee weapon. So I can have a spell storing dagger. A dagger can be thrown.

So my 5th level 14-strength magus throws my throw-able spell storing dagger stored with a Shocking Grasp. The attack passes. Does the spell cast? The dagger deals 1d4 piercing + 2 from str + 5d6 electricity, doesn't it?

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Edit following comments

Anytime the weapon strikes a creature and the creature takes damage from it, the weapon can immediately cast the spell on that creature as a free action if the wielder desires.

What is the wielder? The problem is that "wield" is used as just a word and not a game term. Their no official ruling nor FAQ about that (as per a discussion shared by @Hey I Can Chan)

In our case, does the character is still wielding after the weapon is thrown? While I have the weapon in hand, can I chose to activate the spell on damage?

Answer 1

The spell storing special ability can only be placed on melee (= handheld) weapons. This restriction strongly suggests that the ability is meant to function only with melee attacks and that holding the weapon in one’s hand is a requirement to make the magic work.

A dagger that is thrown effectively becomes a thrown weapon. If a thrown dagger could deliver the stored spell it would mean, that holding the weapon in one’s hand isn’t a requirement to make the magic work. But why can the spell storing ability only be placed on melee weapons and not also on thrown weapons? Why can a dagger be enchanted but not a dart? This restriction would not make sense then.

Therefore, I think it is coherent to assume – at least in this case - that wielding a weapon means holding that weapon in your hand and that you are no longer that weapon's wielder as soon as it leaves your hand. Following this, a hurled spell storing dagger can’t cast its stored spell, because it has "lost contact".

Answer 2

Yes, you remain the "wielder" when you throw a melee weapon.

I would rule in favor of allowing you to activate the spell on a damaging hit with your thrown spell-storing dagger based on the following quote from the Thrown Weapons section of the weapons rules:

Thrown Weapons: The wielder applies his Strength modifier to damage dealt by thrown weapons (except for splash weapons).

The user of a thrown weapon is explicitly defined by the rules as a "wielder." In fact, this sentence defines the thrower as a "wielder" in the context of what happens after the weapon had left his hand (i.e., the damage roll). To me, this implies that you remain the wielder of a thrown weapon through impact and damage. This should then allow the wielder to trigger the stored spell, which happens immediately upon the damage roll for which the thrower is still considered the wielder.

The rules are not entirely clear, and reasonable people might disagree with me, but this is how I would rule it.