Noticed this in a letter printed in “Bike” magazine (Feb.2004). Apparently some bike insurance policies do not automatically cover you for carrying a passenger, in fact some even state “Carriage of a pillion passenger will invalidate all cover”.
The one mentioned was Equity Red Star, but it may apply to others.
Apparently in this case the rider contact his broker and pillion cover was added at no extra cost.
I am off to read my policy properly…