I guess the difference is not in the transaction itself.
The key part is that insurance counteracts a risk on your part: If it lowers the variance of your final balance, it's insurance. If it raises the variance, it's gambling.
When I was at Microsoft about 15-16 years ago there was a fairly big poker setup. Where I was, and I'm sure across the board, the advice that was given was that we were free to have tournaments on company property, however, one of the rules were that you could never actively bet truly blind, i.e. you had to see your cards first. According to whomever decided that, that was sufficient to keep your poker game a game of skill, and not gambling, since if you didn't know your hand, you were just relying on luck, not playing odds.
Well, that line mostly boils down to whether the expected value of the bet is positive, and the insurer in the article seems to do pretty sound analysis to ensure his expected return is positive. I don't see where it gets close to gambling.
One should keep in mind that the literal "best odds", as far as i know, at any casino are on "Don't" bets on craps, after the shooter lands a number and the button says "ON". With odds on your Don't bet, you can take the house edge down to 0.13%, or 13 cents for every $100 you bet. If you don't feel like "laying odds" you can place "Come" bets with odds behind them for 0.16%. I rarely play don't, but when i do, i'm the shooter!
I am not sure insurance v. gambling has anything to do with expected value. Typically, I see the distinction as protecting something you already have compared to getting something new.
The insuree feels like a gambler to the insurer/house, but they never get the money. Their goal is the exact opposite of gambling, to pay a fixed fee to remove variance.
