He is required by law 2 have a load sheet signed by both the Dispatcher and the Captain and was breaking the law departing with out one.
I hope you reported this incident! imagine what would of happend if a problem would of happend with the aircraft and the governing bodies had requested the loadsheet for inspection? what would you have done then?
Why did the despatcher not radio or call you and request a new loadsheet with the correct figures on? it would have only taken 5 mins 2 knock a new one out!