Disaster possibility 1 is that nobody bids on the project. It is too risky.
Disaster possibility 2 is that the original bid is met... but one critical feature is left out of the contract (overlooked) and is thus not in the result.
Disaster possibility 3 is that the company does go bankrupt. Uh, oops, we needed that company. Now we can't get parts for other products. This could be fixed via a huge bailout.
This is a problem that cannot be solved by hard and fast rules.
There needs to be a decision making process that can guide the R&D project.
Unless of course goals, progress, etc. can somehow be quantified. (But these are complex projects, complex goals, even coming up with relevant metrics is hard, and somehow coming up with one utility function is kind of impossible - without spending a lot of money on R&D for that, but then you're back to square one.)
That said, yes, risk should be better spread, but also the following are all critically related to public spending/procurement: Personal accountability and motivation, too big to fail, cartel/oligopoly, agent-principal problems, corruption, institutional deadlock, too much bureaucracy, bad responsibility-authority allocation, etc.
