The old "Orb Quest" microgame & Shields

[Drakenbow]

In the game Orb Quest I noted this line.

204. "Curse you all!", screams the wizard, as he stands and grips his staff (1 die damage) and small shield. He is ST 13, DX 18(16), IQ 16, MA 10(8) and
is wearing leather. He also has on an amulet/strength battery around his neck worth 20 strength points. He know the following spells:
...(I omited the list)...
If using TFT: IN THE LABYRINTH rules, the wizard also is considered to have the Shield talent.

Was it intended that a wizard could use a shield and still cast spells?

Although it is not said in the quest, I would expect the shield to be silvered. I would not think the creators of this microgame would over look issues with a wizard carrying a shield when encounter. In the core book I know has the Iron, Silver, and Magic section on p.140. And I am aware of the Wizard Staff has options of being a dagger or sword (preferable silvered) from p.148. The Gestures and Incantations on p.142 suggests with an IQ 2 points or higher than the spell being cast would only require one hand.

So, in your opinions can a wizard wield a shield (or non-Staff weapon) in the off hand and still cast? Does the Occult attack from a Wizard Staff imply the same limitations on IQ?