Wow that really sucks. Sounds like unclear signage, more than incompetence or something. Still, would be really disappointing for folks chasing a BQ, or first timers. Or anyone, really.

I've never DNF'd a half marathon (my longest race) but if I did, and I'd done my best and it just wasn't my day, I think I'd be OK with that. But for it to be this type of error would be aggravating to say the least.