Final house fix update o' the day
Yeah, that just about covers it.
Addenda: The leak was a very small slit in a 3/4" "Quest" (?) pipe--apparently a higher failure rate than polybutylene. 3/4" means high pressure, and in this case, high enough to punch a hole through the drywall after first spreading across the ceiling to drip out of the A/C vent and possibly damage the ceiling fan/light. That section of pipe has been replaced with copper. (Also, apparently the house has no Pressure Regulation Valve at the supply, which could contribute to further failures. In fact, there have been leaks twice before Nathan owned the house, and now twice while he's owned it, because the previous owner declined to pay to have the piping replaced.)
Also: Called ADIC HR, left messages, since I was supposed to hear back "within a week" of last Tuesday's interviews.