The dealer IS responsible, as a representitive of the manufacturer, to handle warranty issues, as well as to serve as a go-between with customer and manufacturer in a situation like this one. So yes, the dealer dropped the ball, then promptly kicked it into the weeds.
Even as the owner/purchaser, Brian (LC) isn't the final say so on who is responsible for dealing with warranty claims. That is pre-determined protocol, established by New Holland. That MAY have been followed initially, but obviously went off axis at some point. Most likely, there was/is issues with this tractor that stem from improper assembly, BUT, at first signs of trouble, it's the dealers problem until such a time as it's determined to be the responsibility of a "higher power". (ie NH) In so many words, the DEALER has to be the first line of responsibility. He tried, but obviously, failed miserably.
By the time the dealer was willing to get the NH rep involved, BRIAN had already done so. He had to do the dealers job for him. At that point, I suspect the dealer was feeling the pressure to jump on the "call the parent company" bandwagon and just went along with what Brian had already beat him to.
IF THIS SITUATION WOULD HAVE BEEN HANDLED CORRECTLY, AND IN A TIMELY MANNER, BY THE DEALER, the problem(s) would have been solved, and the NH rep wouldn't have even known what happened.
New tractors have been known to have issues. They get fixed when that happens. That's the DEALERS responsibility. The DEALER choked. From the point where Brian very first informed the dealer's service dept there was a problem, until the point where we are now, all that has transpired is the DEALERS fault. They get to shoulder that responsibility when they accept your check on behalf of New Holland (or whoever)