Has anyone booked UA flights at some third-party site for a lower fare?

Google Flights shows fares from one of these sites, because it's much lower. When you select the segments and go to the page with the booking link, you see that to book from UA or from any Star Alliance partner such as Austrian is much higher.

So the low price for this one flight I'm looking at is from business-class.com.

I haven't clicked through to see if there are some strings attached. In this case it's $500 lower for a round-trip business class to LHR.

As tempting as it is, it must still be the rule that these non 016 tickets, especially from some 3rd party which is not even a Star Alliance partner, would not earn all the PQPs and RDMs, so not as useful or maybe not useful at all for status earning.