My guess is that, in the vein of the "monitor flickering" symptom, your PC sees the DP/HDMI cable disconnect and reconnect due to the static. The reconnection wakes it up.
I don't know. Manually {dis,re}connecting the cable doesn't wake the PC up, but it's too hard to reproduce reliably to tell if having it disconnected makes a difference.
I don't know. Manually {dis,re}connecting the cable doesn't wake the PC up, but it's too hard to reproduce reliably to tell if having it disconnected makes a difference.