Are you asking if the bid withdrawl is legit, or is it more of a question about professionalism? As a hop producer and processor I appreciate having some sort of agreement with my brewers so I do not over-sell our crop. However, using a contract as a means of force to corner a customer or blackball a customer is just bad business. Traditional hop brokers have had their run of their customers for years because ..."where ya gunna go?". Now that other regional sources are cropping up there is a shift by the large brokers to marketing licensed, proprietary varieties to once again force their customers back into the pen.
Most of these contracts have a "force majeure" clause somewhere that is the golden get-out-of-jail-free card. So the "contract" most likely will not protect you if there is a crash.
Now, ask yourself if the 2008 "shortage" was simply due to a few unfortunate accidents or was that just an excuse to run up prices? No finger-pointing here...but we have to ask these questions.