Tomas connected to my computer via Teamviewer and did some troubleshooting this morning. After verifying that my setup was correct he discovered that the Spirit had lost it's sensor calibration which I belive is set at the factory. This only affects rescue and it was the first time in 15 years that this had been observed by Tomas.
After a recalibration of the sensor rescue now work correctly.
So, this issue was caused by an extremely rare fault in the gyro. But something that can be fixed remotely via a recalibration.I will not speculate on how this happened but if it was the first time in 15 years it is unlikely to happen to anyone else soon. Nevertheless, verifying your rescue operation on the ground should be advised.
Thank you so much to everyone that contributed to solving this issue, you are a credit to the heli community in that you did not give up suggesting steps to solve the problem even if we were bashing our heads into the wall.
And of course thanks to Tomas for excellent support.