One of the perversities of making sh*t up about dogs is that it allows people to continue to use force, intimidation and scary punishment to get their dogs to do what they want. The mythology of the pack leader ranks high on the list for this.
I am not going to reinvent the wheel in regard to explaining that dogs don’t need pack leaders because they are not pack animals in the same way wolves are. You can find lots of information about that from bloggers, trainers, and field biologists. But I will encourage you to imagine what a person’s acceptance that dogs need a pack leader can mean to an animal that survives by the millions without one, thank you very much. It’s like suggesting to a parent that they need to brush their baby’s body every day even though they don’t have fur.
Is this person being a pack leader or just an a**hole?
Dogs are incredibly adept social animals. They have a wide-range of behaviors that help them avoid or minimize conflict among their peers, and the humans they live with. When one of those humans tries to pretend to behave the way they assume a pack leader would behave, imagine how that could be perceived by the dog. What those who know what they are looking at observe is that the dog is on the spectrum of concerned to flat-out scared.
But then again, if dogs have a sense of humor they might just be chuckling watching the human spitting in their food, scurrying out the door first and laying claim to property in any one of the ways recommended by the folks adept at making sh*t up about dogs.