What should you let your dog get away with?
Your dog breaks command after 30 minutes, your dog sometimes does not come back to you, your dog is a "selective" listener.
What should you allow your dog to get away with? How you want your dog to be. Its as simple as that, what you allow your dog to get away with is how your dog will be over and over again.
So if you want your dog to be reliable make sure that train and hold your dog accountable on a daily basis, every single time.