FAQ Question: Fireball spell section is confusing

[XMark]

According to the FAQ, 4.3.1:

What kinds of wounds does a Fireball cause?

It is largely an impact weapon; a baseball-sized bolt of pure magical force. This is why it's damage is stopped by the DR of the location hit. It is hot, and it does vanish in a gout of flame when it hits the target, but that's more of a special effect than it's primary mode of doing damage.

How does a Fireball interact with armor?

This "hard" bolt of magical force hits the armor just like a bullet, staff thrust or fist, doing damage on impact, and either denting it a little or punching a hole straight through. It then goes ``Poof!'' and vanishes in a cloud of fire. It will only heat up a breastplate as much as a baseball-sized globe of 300-degree air would; i.e. not much.

Does resist fire then help against a fireball?

Does unsealed armor protect against an Explosive Fireball?

Yes. Here's how it works:
The Explosive Fireball does flame damage -- treat as crushing damage that can set fires. It is not a true explosion, but damage decreases with distance in a manner similar to explosive concussion damage. The target may attempt to dive for cover to get away from the center of the blast. DR protects normally; assume torso DR unless the target is hit directly by an Explosive Fireball aimed at another body part.

Is the damage done by a normal fireball different from the one from an exploding fireball?
In addition, GURPS Magic says fireball does burning damage, not impact/cr, which seems to contradict the FAQ above.