2007 Buick Rendezvous CXL - Weird power window issue

[pokepoke]

I had my master cylinder replaced last week and when we picked it up from the mechanic the windows quit working. The mechanic claims they didn't do anything so it's my problem to fix this. I've been investigating and scratching my head over this for awhile now. Here's what I've determined:

1. Found a broken wires in LR door harness at hinge and repaired them successfully. Not other harnesses appear to be bad
2. Windows will not power up or down with doors closed. Voltmeter shows 2 volts at switch when trying to roll them up. You can hear the motor pushing, but it doesn't have enough juice (short?)
3. Windows will power up and down if the driver door and any of the other 3 doors are open (driver door cannot be shut or it won't work). Getting 10 volts at switch in this condition
4. Closing the doors isn't necessary. The test above works if you just engage the door locks with a screwdriver. Latches and locks work correctly.
5. I've inspected the wiring all around the driver side compartment and center fuse box and found no loose or damaged wires. Same in engineer compartment
6. I tried pulling every fuse individually to see if isolating any system would make them work and it did not. Pulling several unrelated fuses caused no voltage to the switches though (such as rear defrost, lift gate, heated mirror, power sunroof)
7. Oddest of all, but maybe unrelated, when I pulled the BCM 10A fuse in the center console with the ignition on the car started on its own
8. At one point this weekend the windows were working all day unexplainably. I tested them with engine off, while reversing in the driveway and they worked, the moment I put it in drive they quit. I haven't been able to reproduce this.

I'm at a loss of what to try next. Any suggestions would be greatly appreciated.