I was thinking the same, if the herd sizes are small and management goals are in the same direction, You may both be money ahead and have better relations if you shared a bull. Perhaps ask him if he knows of any bulls he really likes, and if you like it too, sell yours and buy that one.
I know I'd want some proof it was my bull that killed his before I pulled out my checkbook, but I know that proof or no proof relations would suffer if I didn't pay... I know I'd feel that way unless it was absolutely undeniable that my bull had died of other causes.
pdfangus, that's impressive, partners even after a death!