"A 7-year-old Australian boy miraculously survived an attack by an aggressive kangaroo using a defense method... 'the kangaroo roll.'"

"'You put your hands around your neck and you roll up in a ball'.... The boy proceeded to put his face down and scream for help."

Miraculously? How dangerous are kangaroos? Here's a Slate article from 2012 (after 3 kangaroos escaped from a zoo in Germany):

Although the last recorded death came in 1936, there have been several kangaroo attacks in Australia in recent years, some resulting in serious injuries.... The best defense is to keep a safe distance and try to create a barrier between yourself and the beast. Even holding up a large tree branch can be helpful. If the kangaroo approaches, turn your body sideways, exposing a narrow profile to the animal and protecting your face and organs. Raise your hands and lean your head away from the animal to minimize the chances of being scratched across the face by the kangaroo’s nasty claws. Retreat, but do not turn your back and run. A kangaroo can easily chase you down, kicking as it hops.

At the internal link, 2 of the stories show kangaroos attempting to drown somebody's dog:

November 2009... 49 Year old Chris Rickard was walking around his property together with his dog, a blue heeler named Rocky. They stumbled upon a sleeping kangaroo, who woke up and tried to get away, chased by the dog Rocky. The kangaroo them jumped in to the water and the dog followed. In a self defence move typical for kangaroos the kangaroo grabbed the dog with its front paws and held it under water to drown it....

July 2004...  Christine Canham was walking her four golden retrievers around Dunlop Ponds in Canberra's northern suburbs when her dog, Summer, had a run-in with a kangaroo who then held him under water and drowned him. Drought conditions have made the kangaroos change their usual behaviour and become active in daytime and fiercely defend water sources and feed patches....