Let this be a lesson. . .

At our electrical inspection, the inspector was fairly complementary of our work, of course most of it was done by an electrical engineer (Jens) but we weren't going to tell him that. He picked up our permit sign-off sheet, clicked his pen, and stopped, "are you going to run phone lines too?" In retrospect, this is an obvious setup but innocently we reply, "yeah, data and cable too."
ERRRRRRRRRRRRRRRRR! Wrong answer!
Apparently, the electrical inspector DOES care about low-voltage lines in your walls. So we got to work on it.
Deder was diligently drilling holes and dragging cable one morning, all this after the new plumbing is in (now in the ceiling rafters and not in the floors) when the predictable happened. Drill bit meets new hot waterline!
There are several lessons that can be learned here:
1. if you can see the other side of the rafter, it pays to take a look first.
2. PEX is not impenetrable but is reparable.
3. ALWAYS have a quick shut-off valve for the whole house.
4. it never hurts to have LOTS of towels.
5. on the bright side my water pressure is GREAT!