Yes, they won't let other snakes or people near their food. without proper management, a food-aggressive snake can escalate past growling and using it's body to block access to the food, and may eventually bite or attack someone or something approaching it while eating. for this reason, it is suggested that when your snake is a hatchling, you take its food away from it as often as possible, to discourage the idea that it can boss you around with physically intimidating behaviour...
I have kept Olive's since 1990. I am well aware of a food response vs a defensive response. "Food aggression enough to take on a Crocodile" what a load of bull s. Olives have evolved to eat large prey items including pythons, crocodilians, mammals, goannas etc. Its not aggression its part of their diet.
As for taking a meals away...that works on the premise that snakes have a learned memory capability that you can exploit...I will disagree with you on that. Frankly I am not "bossed" around by any of my snakes as I am capable of handling them regardless of their mood.....I would hope every other keeper would be the same....if you are not able to keep it properly- and that includes being able to handle it then the snake is not for you.
Cheers,
Scott