Your intuition is correct, and what you’re describing is cavitation - which the article goes on to mumble about a little. Honestly, I am also struggling to see what the novel result here is. You can snap off a drip of pitch by pulling on it - if you shear it, it will probably just bend - yank on the droplet and it comes off with a satisfying snap.

But then again I suppose if you lead a cosseted life, never played with the contents of a shed, and had your first practical experience of actual hands on behaviour of viscous liquids in a lab… you might shout “Eureka”.