My cats have a tendancy to regurgitate their food... Between the three of 'em we have it happen quite often.
Fortunately they tend to do it in a room Pixie doesn't have access to, or I'm sure she'd eat it too! I used to clean it up right away, now I just leave 'em. The culprit usually eats it again right away anyway.... Why not? It was probably only in their stomach for a few minutes and hasn't even begun to be digested!
I don't think an occasional cat food snack is going to do too much damage, but I wouldn't make it a regular occurrence. Cat food is generally too high in fat and protiens for our pups and could eventually cause health problems if eaten regularly.
And I agree, it is gross... But then again, it's no worse than when she plays with kitty hairballs and snacks on "litter box treats"