Do you have a legal citation for this? I'm unaware of any law that supports this assertion.
In any event, the representation in question is "I want to fly from city A to city B." It's pretty reasonable for an airline to conclude that when a passenger makes this request, that is in fact their intent, not to fly to city C.
As far as I am aware, no one has actually attempted to make a fraud claim on the grounds that mere purchase (and/or the statement of intent to purchase) a composite good or service was a representation by the buyer to the seller of intent to use every portion of the good or service so sold and had the case survive to a published decision on that question.
But, you know, if you can find a case supporting your claim that this intent would clearly be inferred from such an aggregate purchase, I'd love to hear it.
So when you agree to use the ticket to travel all the way to the final destination, I think that qualifies as a "representation... of intent to use every portion of the good".
Airlines can’t have it both ways: if they wanted to, they could make customers pony up a “trajectory abandonment” deposit, or force customers through an interstitial in which they explicitly agree to extra charges, or something similar, but they want the financial/competitive advantage that comes with the customer not having any worries (i.e. being clueless) about being charged for missing or not taking a connection.
One could argue the same about every post you've made on this topic thus far. You're arguing that simply the act of buying something is a representation, which can then result in misrespections ala fraud, but you've provided no legal citations and the one citation you have provided was about contractual agreements which aren't in scope here.
How does buying something indicate your intent, wants, or wishes? If I buy a can of spray-paint, the store has no idea if I am using it to paint my child's bicycle, tag graffiti, use it as a weapon and hit someone on the head, or as part of a wonderful "Rube Goldberg" device which at the end an implement hits the sprayhead which sprays through a bright white light as part of performance art.
Another example, a true story: yesterday I visited an ice cream store with my friend. She wanted a scoop with chocolate sauce, and I wanted just a scoop. 1 scoop was 4.29+tax. A 3 scoop sundae with chocolate, nuts, and strawberry-sauce was 7.98+tax. Even though we only wanted 2 scoops we got the sundae because it was cheaper and scooped the strawberry-sauce off and into the trash (crazy I know, we don't like it). Did we defraud the ice cream store?
People buy "more than they need" all the time, and purchasing a good provides no intent as to what one wants or how they wish to use it.
Because when you buy a united ticket you agree to a contract of carriage that specifically says you will use the ticket in its entirety.
And what makes it most ridiculous is this: "Any practice that United believes, in its sole discretion, is exploitative, abusive or that manipulates/bypasses/overrides United’s fare and ticket rules."
Can they ban me from United- yes. Can they try to collect money and threaten me with a credit dent? They can, until they ran into a lawyer or into a motivated person with time and resources on their hands.
Apart from proving that you intentionally bought a return flight best of luck defining this as fraud in front of a judge.
I booked two flights to Paris for my girlfriend and me. Before we left she found out that she has to return a day ealier. Instead of rebooking the flight (which would have been insanely expensive) she chose to return by train.
Arriving at the airport for the return segment I proceeded to the gate and informed the airline employee that my girlfriend will not make the flight and that I would like to check her out.
Instead of busting me and denying boarding (which would be the logical conclusion of your asessment) she thanked me profusely and I went on my merry ways (waiting for and eventually boarding the flight).
Now, you can certainly argue that we didn't know about her earlier return when booking the ticket. But we sure knew about it when boarding for the first segment. Nevertheless and despite the tickets running under the same record locator I did not have any problems boarding the return flight nor was I approached by the airline later.
Of course it could be that European airlines are generally not as hard nosed as United (they generally also don't rough up their passengers, but I digress). But I think it's more to the point that it's impossible to prove that I never intended to take the return flight. It certainly would be more obvious for hidden city / nested bookings strategies that I intended to save money (I would be very reluctant to call that fraud).
Moreover, fraud is a criminal concept. Violating the contract of carriage is certainly not.
But the language of a contract of adhesion doesn't seem likely to be taken as a representation by the non-drafting party in a fraud case.
Now, there could be something United has inserted in the purchase flow of all multileg tickets which assures that the purchaser makes a representation of intent to use every leg, though I've never seen anything like that when purchasing tickets (and a contract of adhesion that United writes that most purchasers will not read, while it may succeed as a contract, probably won't be seen as such a representation for fraud purposes, AFAICT.)