If a dog happens to eat a bit of raw hamburger meat then nothing should happen as it's safe for dogs to eat some raw meat.
Although when a dog goes on a raw meat diet you're supposed to boil the meat for a minute or two to kill bacteria in the meat to prevent the dog from getting sick.
But dogs can safely eat some raw meat without getting sick.
Just don't allow the dog to eat too much raw hamburger without boiling it first just to keep the dog from getting sick should the raw hamburger contain some bacteria.