I love dogs, but I don’t love dog behavior like this. I wouldn’t want to be around that dog, either.
Is this their first dog, by chance? I hope they don’t have to learn the hard way that that type of behavior is a liability for them. If the dog hurts someone by jumping up and knocking them down, they (and the dog) could be in trouble if there’s an injury.
Good luck trying to get them to change, though. They probably won’t. It’s people like this that make it hard for people who do teach their dogs how to behave.
My dogs are pretty mellow but if I have people over, they go outside. In extremes of weather they’ll come in and go in the sunroom with the door closed so as not to bother anyone. Often visitors tell me I can let the dogs in. Dogs say hi then they go lay down. Last week we had friends over to eat and a movie and during the movie the little one layed between them on the sofa and they patted him, saying let him stay, otherwise I would’ve put him away or put the gate up.
This doesn’t happen by chance, it takes a lot of direction and consistency to get them to understand the rules. But once they do, and they’re enforced all the time, they generally behave. On my 7th German Shepherd now and I also have a Cairn Terrier, who’s a great dog. I’ve known a lot of retrievers who are friendly but food mongers. One friend had a big Black Lab behaved like the one in the OP. When our kids were little they had us over once for a birthday or something. We were having cupcakes when the dog jumped up, grabbed one of the cupcakes, and practically swallowed it whole! The mom was running around the house chasing after the dog, lol.
Someone upthread mentioned it, too, but daily and hard exercise is really necessary for some of these dogs who were bred to work. They don’t know what to do with themselves when they’re just cooped up all day, and their energy comes out as chaos. With more directed energy, like a run, or playing ball, or playing with other dogs, life can be so much better. A tired dog is a happy dog.