Ugh. It's this kind of crap and the actual belief that OP is justified that ends up with us being called "over entitled" and getting more and more rules thrown on MileagePlus.
OP knew he found a glitch. But the computer system let him, so he thinks he's self righteous and justified because hey, United made a mistake and that's their problem and he got his and everyone else can go screw.
Now he's caught, and of course everyone is so cheap and entitled that they won't just pony up the coupon they owe - they try to get the dang GOVERNMENT involved?
Loop or circle or not, it's a round trip. 2 RPUs. (Last time I checked loops and circles were round, btw.) We all know the <4 stopover is a glitch, so what you DON'T do is whine when you're called on it. You play dumb and take your licks.
If we on FT are going to throw a conniption every time United doesn't make good on their mistakes that harm us, we at the very least can't literally start a federal case when they catch us in a mistake that benefits us.
Even if you used 2 RPUs, odds are that half the legs won't clear - so your complaint is about as petty as it gets around here. Pony up the RPU or sit in back. Don't waste my tax dollars on a frivolous DOT complaint.