Their mistake was not in dropping out. If a marathon is going poorly, there's usually little reason to finish it, struggling, and perhaps damaging future racing. Some very top quality elites dropped out this past weekend, including a guy named Merga.
But that's irrelevant. What is most irritating about Biz (and the whole McMillan attitude) is their arrogance. McMillan asked for a faster pacer. Originally Pinkowski had the rabbit going through in 65:30-66:00. McMillan wanted 64:30, and asked for his own pacer, Martin Fagan. So Pinkowski didn't bother with the slower (more reasonable) group, and McMillan got his way - subsequently f***ing up a perfectly legitimate pace group in the 2:10-2:11 range.
When you get down to these times, 1 minute here and there makes a big difference. And that entire group: Fasil, Carney, Nick A., Boaz, Young, two Japanese guys, Biwott all suffered and eventually dropped out. McMillan was irresponsible and selfish. Especially considering that his guys were simply not ready for that pace. Carney just struggled in April to maintain a 2:12 pace. Biz. has had nothing but trouble in the marathon, always going into it overly ambitious.
Nick A. is probably the only guy in that group who was justified in reaching for a 2:09:00, based on his previous time in Arizona. But still, a 2:10 would have been another breakthrough for him. 2:09 flat was dead wrong. A lot of the blame for how this particular group responded lies in the lap of McMillan. He errantly persuaded his group to go out fast, and if they fell off they would fall off to a 2:11 or so. Well, that's not how the marathon works. It's just poor coaching. And unfortunately his decision/arrogance effected the races of several others as well.
Kudos to Hartmann who had the sense to recognize early that the pace was too quick, backing off, and running a reasonable tempo to the finish.