Of those who are aware of the specifics personality and attributes of this breed, it is the majority opinion that a Dogo Argentino type of breed should not be owned by an inexperienced owner
You seem to have been aware something wrong was going on before - that the dog hated this guy before this recent attack. This behavior seems pretty irresponsible.
PLEASE read the following info about Dogo Argentino:
"Dogos are big-game hunters and are sometimes trained for search and rescue, police assistance, and military work. Due to their physical capabilities, they are not common family pets, though they are sometimes kept by experienced dog handlers."
"... Dogos Argentinos are protective of what they perceive as their territory and will guard it against any intruder. They get along with other dogs as long as they have been properly socialised, but will usually not tolerate another dog trying to assert dominance over them and might not coexist peacefully with another dominant breed of dog."
"The Dogo Argentino was bred primarily from the extinct Cordoba Fighting Dog. It was bred to reduce certain aggressive traits inherent in the Cordoban Fighting Dog, specifically its lack of ability to hunt cooperatively in a pack, as the breed was intended to function as a cooperative pack hunter. In particular areas of the world where dog fighting as a bloodsport remains culturally acceptable, Dogos Argentinos have been used for fighting. Dogos of these lines are extremely aggressive and not suited for big game hunting, unlike the original Dogo Argentino breed .
In the United Kingdom it is illegal to own Dogos Argentinos without specific exemption from a court per the Dangerous Dogs Act 1991, and dogs of the breed may be seized by the police. The maximum fine for illegal possession of a Dogo Argentino is £5,000 and/or up to six months' imprisonment. Breed-specific legislation varies in the United States, with bans on the breed enacted in Aurora, Colorado and New York City. The Australian government has banned the importation of this dog. The dog is also illegal in New Zealand, Norway, Iceland, Portugal, Romania, Singapore, and Ukraine. The ban in the UK has received criticism with a spokesperson from the Royal Society for the Prevention of Cruelty to Animals stating that the law must "focus back on the real problem... the owner."
Clearly you are unaware of how badly you need to have yourself and the dog trained for EVERYONE'S sake who lives near you. DO NOT WAIT.
Depending on what type of activity is going on at the time, this type of dog can be like having a loaded gun. You, the person who was bothering the dog and the dog are all lucky the dog did not permanently maim or kill the person.