Agreed. It's just a sub panel off the main. Could be 10 sub panels deep and it wouldn't play havoc with anything. The inverter syncs with the line frequency then boosts its voltage just enough to see it push current into the grid which is a few hundred mV. I would even hazard a guess that the impedance between the panels is enough to say that the current is likely being pulled directly by the closest loads: the tenant's loads.