When Vendors Attack

From time to time I hear the most outrageous tales of horror involving IT. Sometimes they are comical (okay, mostly) and other times the mind is simply boggled.
I find university relationships with vendors to be very interesting. We (the university) spend millions of dollars on products and services from vendors worldwide. Usually there are bid processes that are gone through for the at least appearance of fairness. Other times, deals are brokered for discounts while at lunch or on the golf course. In the 80s and 90s my institution had a sweetheart deal with a certain IT vendor (we'll call it The Angle Co for this tale). Needless to say all IT machines on the campus were from The Angle Co brand. Our user community really didn't like the lack of choice, especially since they could get cheaper and better services from other companies. (Wasn't really a sweetheart for us) Changes in mindset and new leadership in central IT brought competition back to our campus. The Angle Co was no longer the top company. We still used them for certain services, but not all like we had previously.
So that is the back story. I realize for many of us, it is already a horror story. Having to use only products from The Angle Co?!!!! It goes against everything I as a geek believe in. The real horror is still to come.... when the vendor attacks!
The Angle Co was approached last year (along with other vendors) to support some research and development efforts by the institution. Researchers were seeking federal money and wanted to use The Angle Co's Y machines for some mutually beneficial research. The Angle Co stated in a closed door meeting that since the university was no longer exclusively using Angle brand, they didn't want to partner with our researchers.
While The Angle Co certainly did not have to partner with us, I think this still stinks of extortion and makes me very concerned for IT choices on campuses. Let's say (hypothetically) that Professor X is a big deal at his (state funded) institution and in the state. If Professor X is told that he cannot have his machine because some lowly tech guy wanted to purchase machines from other vendors, what are the potential ramifications? The institution cannot afford to anger Prof X. Very bad publicity especially during a time when we are looking for state funding. Headline would read that we cost the institution millions of dollars in research funding (because of the lost grant and potential savings in the technology). How insane is that? While this hasn't (thankfully ) happened here... what about the next institution? How can we stop companies from pressuring administration and IT folks from making these sorts of forced purchase decisions?