@kwired
Yes, imbalance. But I mentioned that, if one load shorts itself then 240v will (might) be on the other load, and poof.
Since what, about 1980, resi panels are fairly ok being "balanced" across both lines, as the practice became better at doing things?
There's likely two scenarios to be had.
1) the resi is an electrons saver so they keep everything off, in this case using one load means it won't turn on, then they try other siwtches and stuff, nothing works, they call someone.
2) the resi has all sorts of stuff on all the time, the more stuff 'on' the lower the imbalance will be across loads (bc's) that are looping amps from one pole to the other.
And then you have that most N bars in panels are stabbed to Earth, so unless the example of issue is a fully floating N bar, there's likely still amps flowing pole to Earth. You can create a test model of this using a small low-v CT xfrmr, just tap the CT at shared load point of connection to a ground rod, then lift off the CT at xfrmr, what do you get?