Ours is a sweet dog and eager to please until the scent of a prey or the sound of a vehicle waft by. GSD, out of a K-9 breeder that we have had several from in the past that were trivial to train. This one is bright, excitable, and much harder to get her to focus on us, distracted by her own internal excitement, or by something. That behavior is a sharp contrast to the prior dogs who watched for our slightest fidget or gesture.
Generally she is extremely reliable, but yes, if she lights the afterburners, "come" is not something that she hears. She is laser focused on the intruder. Otherwise, "come" is quite reliable. Ditto, in the house, when she can be fast asleep, wake up, and feel the need to defend the house from unseen forces. Loudly. She seems very inconsolable about it, even if I sit with her, pet her, or hold her (she likes whole body snuggles normally). I'd just like to help her not be so off the charts internally in excitement, as I would like to have her be safe.
All the best,
Peter