The trouble with telling your insurance up front is that although you may never need their help..you are telling them about a possible claim if things go wrong..and whatever the outcome it will be logged.
A friend had the same and although the other driver paid in full it did affect things later. although it goes down as a "no fault accident" it's like they don't quite believe you!!!!
I'd see what happens and hold the insurance notification back if the other guy tries to wiggle out.. It's amazing what the thought of their insurance premium going up for a few years tends to get them to cough up.
