with the loss of a motor nothing short of a miracle can stabilize it,when deciding on my drone type i checked out the yuneek[i think] that had 6 props,could lose one and still fly,wish it had more intriguing features as i may have bought one.
It is possible to stabilise and "control" a quad after losing 1 prop (or even 2 opposing props). It required giving up yaw control. . They cut off 2 propellers and were able to safely control the drone. The underlying control algorithms are however rather advanced/complex. but even without the camera position system they used here it is still physically possible.
losing 1 prop, detecting it, shutting down the opposing prop, switching to 2 prop mode and increase allowed energy draw/speed from remaining props, land in a controlled way.