I tested it in the lab, also in the AP mode the fallback doesnt work, bc the br1300 is connected to the powerinj. so the bridge never see that the fastethernet link goes down. so it seems that there is no solution for that. cisco must implement a feature that checks the status of the interfaces on the powerinj. show powerinj. and if the ==Power Injector port 1 link down then the radio should shut down also.