Just goes to show you shouldn't bank on any one deal coming through. As the management of a company, its your job to have not only one deal in the works, but preferably multiple deals, so called "deal flow" or "sales/prospect pipeline". You should be in constant prospect mode, and never give any one prospect any significant portion of your time. It's not like it takes a lot of effort to just talk to people. I realize its time consuming, but what we're you guys doing in between talking to this guy? You should have been working on other deals. That way if one doesn't work out, you can rely on the others and leverage them until your own bullshit wears out.
This is the proverbial case of "all eggs in one basket".