Well I don't know....

The shelties get kibble and raw all the time. Somtimes I feel like giving them a whole raw meal and they don't get kibble that day, and sometimes I only feel like giving them half of a raw meal and so they get kibble as well.
Additionally when they get a rec bone it's almost always on days they have kibble. Again, never a problem.

So I know that doesn't help you any, but just wanted to share my side.

Perhaps Gonzo just has a sensitive stomach? Or perhaps fasting him before giving him a bone will help. Or perhaps he just doesn't do well with beef bones. Who knows. If you'd like the link to another board I post on with many knowledgeable people who feed raw please PM me.