It appears that at least part of the areas that the hair didn't slip on might have a little fat left on which will make the hair harder to remove. The bubbling you mentioned is just caused by heat & gasses build up between the fat & membrane & the hide, same effect as bloating. I'm assuming you used a lime solution since you used the term slip. If you flesh it out good before soaking it, the hair will slip more easily. I agree with Oltoot, I'm one of those who sometimes gets a little lazy with my fleshing as long as I get the fat off good, but I don't always get that real nice translucent look over the whole hide (Thanks Oltoot). Overall looks good, should make you some nice rawhide. Buck