Well, that use of jealousy is only really common in certain romantic situations. Like if some super good looking dude hits on your girl and she responds in an ambiguously-flirty way, you might definitely be said to be jealous, even though she didn't run off with him.
I read that link as supporting the distinction, not refuting it: "It is difficult to make the case, based on the evidence of usage that we have, [that they are] exact synonyms [or] totally different words."
An envious person would be happier having something that someone else also has. A jealous person feels threatened that someone else has or wants something. This distinction applies in romantic and non-romantic contexts. Both emotions can arise, for example, when someone observes someone else wanting something neither of them has, or when the thing wanted is inherently exclusive.
I don't lose a lot of sleep worrying about others' use or misuse of these words. But I do think it's essential for people to understand which of the two emotions they're having, because the solution really depends on that. Would I be happy if I destroyed that other kid's toy? (That's jealousy.) Would I be happy if my dad showed up and gave me a similar toy, so that the other kid and I could play together? (That's envy.)
Jealous is when you possess something you don’t want taken away by someone else