with enough patience, time and training it is actually possible to predict their reactions and have 100% control over them. when I take him anywhere without a leash he is always heeling unless we are in a dog park where he is allowed to run off leash. Ive tested him with trained and experienced dog people by having them fire starter pistols right next to us while he is heeling, sitting, laying down on and off leash. I have had them come up and pretend to be attacking me, even throwing me down on the ground and sitting on top of me. he will get defensive, barking, growling but I tell him to lay down and he does it without question or hesitation. I've trained dogs for 13 years. personal dogs trained in obedience, conformation shows, schutzhund, herding, I've trained my dogs and other peoples dogs in those and agility. I've trained dogs for SAR (sorry, SAR stands for search and rescue) groups. I've trained for the military as a civilian consultant, and for police agencies. I've trained everything from german shepherds to rottweilers to golden retrievers and bloodhounds, jack russel terriers, and chihuahuas. I charge anywhere from $50 a day to $500 a day depending on what the owner wants the dog trained for. if any or all of the owner, my assistant, my wife, and/or myself dont think the dog and handler are trained to the point where the dog is 100% obedient and trustworthy in and situation possible, then I start over (some of the advanced training sessions are 30+ days long) and the owner doesnt pay me a cent. in that case I also pay them for any travelling expenses nessecary in bringing the dog to me for the training. to date I have not had to do that for a single dog/handler. if I did have to I could lose up too $30,000 (15k for the first 30 days, could be another 15k for another 30 days) and would be a deserved loss. the hardest part in training a dog, to do anything, is training the owner/handler. and making them fully aware of the potential danger in training them and there dog for certain things. sadly (from a financial stand point) I have to turn down 75-80% of the people who want me to train their dogs for them because they say or do something to make me think they WANT their dog to be dangerous. I dont train dogs to be dangerous, I train the dogs to be obediant in any situation. I dont train dogs to bite people, I train them to know when it is acceptable, and to be 100% obedient if they do mistake a situation for being an acceptable one to bite. to further show how hard I work to weed out the people who dont need a dog, let alone a dog trained in protection...I could make a decent profit training at $100 a day. but if protection is being trained it costs $500 a day. besides the higher price if you are a potential customer there is a 30 day period where you have to talk to me everyday in email and on the phone where I ask a lot of questions and expect you to ask a lot of questions too. and then the first 15 days of training I dont even think about training protection, its obedience and other things if wanted, and feeling out the dogs personality. if you want higher levels of protection, like for competition in schutzhund, or for military law enforcement then it takes more than 30 days. if at any time I decide the dog doesnt have the nerves for it, doesnt have the right personailty, or that you dont have the right desires or personality, I end the training and contact other trainers to alert them about you.
so basically, yes if you know what you are doing and know how to train the dog it absolutely is possible to train and trust a dog 100% in any situation.