2. He probably got too close to a nesting female. Male geese are the same way this time of year.
They become super protective of the female while she is on the nest. We have a pair of geese that return to our pond every year and we cannot even cut the grass while she is nesting. On the day the goslings hatch the pair brings them right up to the door of the house to be fed. They are wild geese but know we are friendly and feed them. But during nesting season, do not go near.