I also agree. If a human fails to respect a growl and doesn't back down, then, from the dogs' viewpoint he/she becomes the aggressor. Continue and the action becomes one of an agitator. At some point, especially if the dog is a dominant type, it may become aggressive. When a dog is non-dominant it is more likely to bite out of fear when challenged.
I worked training police and military dogs years ago and have much experience wearing a padded suit and being bit.
I was a professional agitator (my wife says I still am) : D
My position on this is, respect the dogs' growl it is the human who needs corrected.