Mold in Corte Madera

I did a mold inspection in Corte Madera last week. I found wet carpet and mold on the drywall along an exterior wall. The home is on a slope and the exterior wall is cut into the hillside. The wall is concrete to a height of about three feet and the exterior grade slopes down to the concrete wall. The distance from the soil to the top of the concrete is about one inch, so it seems reasonable to me that during a good rain, or possibly when the irrigation system comes on, the water may build up and overcome the concrete wall. If that were to happen, then the water would run under the plate and soak into the interior drywall. Very straight forward... right? The contractor removed the moldy interior drywall and then water tested the outside to see if it could be made to leak... nothing! They inspected the top of the concrete foundation wall for any evidence of water intrusion... nothing. It turns out that the water heater, which is in an adjacent utility closet, had rusted through and was periodically leaking water when the level inside the tank reached a certian point. Was I wrong to suspect the exterior wall... no. This is an excellent example of the uncertainty that we face on all projects. Many times the exact source of the moisture cannot be identified until the wall cavity is exposed. I will be doing a post-remediation inspection on Friday and I feel very certain that the mold has been properly removed and the water source correctly identified and corrected. What more could a mold dude ask for?