I also think this is correct. Apart from the fact that any reasonably modern cars will usually go into limp-home modes, or even stop driving, if errors are dete

I also think this is correct. Apart from the fact that any reasonably modern cars will usually go into limp-home modes, or even stop driving, if errors are detected, I seem to remember something about an electric drive motor needing to spin backwards when driving using the combustion engine. That feels wrong as I write it, but I remember it being something fundamental to the planetary "Power Split Device".