Stacie,
You guys may already be aware of this, but the GFCI outlets are typically the ones that may be exposed to water. Kitchen outlets, bathroom outlets, all of the exterior outlets, the outlet in the UDC, and possibly the outlet in the basement. Not sure about the refrigerator outlets, but I think they may be on a separate breaker.
Outlets in the slides are often on a separate circuit breaker with wiring that goes through a j-box on the bottom of the slide. So other than the kitchen outlets, they may not be in the loop.
If he hasn't looked at all of the exterior, basement and UDC outlets, that's where I'd go next.