Rolling out and calling off are two completely different things or at least it is for me. Calling off I thought was getting the dog to back up and not bay. Rolling out is soon as the bulldog and you get there then the dog leaves out. If your on a heard the dog just sticks with them and does t worry about sticking aroun for the bulldog. Or at least that's wht my gyp does and I've been told she rolls out and that's my perseption of a dog that rolls out.
Your perception of rolling out is correct. Calling off can either be calling them off a bayed hog like what your were talking about above or calling them off a track they are running or just calling them back to you when you are tired of hunting and want to go home.