This happened on the old Eyre Highway in SA on the way to the OCR.
Good of the RAC ultimate service to cover nearly all the recovery costs.

Very worn main shaft splines approx 56,000km

Very worn front sprocket drive splines

All the tools used to get the cap screw out to take the front sprocket off
1 Metabo 1/2 drive electric impact
2 Tool Master 1/2 drive air impact
3 Ingersol Rand 1/2 drive air impact
4 Ingersol Rand 3/4 drive air imapact, this eventually removed the cap screw after 2 attempts. I used this for earth mover and truck wheel nuts and large plough disc nuts so it has some power.
The reason it was so difficult.
The last heavy handed mechanic (not the owner) put the cap screw on to the nut torque of 140nm instead of the cap screw torque of 40nm and most likely used the incorrect loctite compound on the capscrew.
Should have been the blue colour loctite compound 243
No way this was coming off in the middle of nowhere
You need to be careful using after market front sprockets as these often have harder steel than the splined drive shaft and will wear out the splined drive shaft.
Normally to replace a worn drive shaft the motor needs to be removed from the frame and torn down as the transmission drive shafts are typically the first items installed into the engine/transmission case when reassembling the motor.