Can Touch Injection discharge unintentionally, or only willfully?

Question

While the spell lasts, you can deliver the substance with a mere touch. To do so to an opponent, you must make a successful melee touch attack. If you hit, the substance takes effect immediately, despite any onset period, and that opponent receives the normal saving throw (if any) against the substance.

http://www.d20pfsrd.com/magic/all-spells/t/touch-injection

If you touch anything or anyone while holding a charge, even unintentionally, the spell discharges.

http://www.d20pfsrd.com/gamemastering/combat#TOC-Cast-a-Spell

Does Touch Injection only discharge willfully, or can it discharge unintentionally?

Answer 1

By the book, the second quote does not apply because the range of the spell is not touch but personal.

So it cannot discharge unintentionally. If you are nitpicking, you could say it does not discharge at all because you are not "holding a charge" as per the touch-spell rules.

Answer 2

This is not 100% defined. Actual touch spells may be discharged unintentionally. This is a range: personal spell that gives you a touch attack, which is not the same thing "legally." That's an edge case in the rules so requires GM discretion.

The description of the spell indicates the poison or whatnot is held in an internal sac and "can" be delivered with a touch attack. That seems to me to indicate discretion on the part of the person with the goo-sack, so I would rule that this specific circumstance doesn't mandate accidental discharge. (Though if someone made Spellcraft to know what was going on I might let them do a called shot to the sack, because that seems entertaining.)