Network/Cabling/Phone guy?
Ask him if he's got Punch/Crimp tools of his own and if he's willing to bring them in until tools can be ordered for him.
Ask him for the color order for a standard RJ-45 jack.
Ask him to describe the difference between plenum cabling and non-plenum cabling, as well as appropriate usage for both types.
From an HR standpoint:
Ask about a time when he was forced to work with a difficult customer and what he did to resolve their issue.
Ask about a time when he was forced to work under abnormal (read: stressful) working conditions and how he overcame them.
Ask about a time that he came up with a unique and interesting solution to a problem no one else could figure out.
Ask about a time when he could not resolve an issue and what he did to mitigate that.
The whole premise here is to weed out the bullshitters. The tech questions are simple and straightforward, no explanations needed. Me personally, I would have issues trusting a cabling guy that didn't have his own punch or crimp tool. Hell, I run cable approximately once every 10 years and I've got that plus a 200ft wire fish.
For the HR questions... We typically use those to make sure that they a.) have the experience they claim, b.) can think on their feet and c.) can maintain a positive attiude when describing difficult customers/bosses/coworkers.
That's what I remember from being involved in the hiring game here.