Was this a failure of process or people?
Neither.
It was a failure of management...
Anyone who conducts a post-mortem with their people would be much better off simply looking in the mirror.
Where were the Vice President of Development and the Vice President of Marketing when things starting going bad? Things simply don't go wrong at the end of the project; there had to have been plenty of warning, if only someone was noticing.
Vice presidents do best by having their finger on the pulse of the things that are important and providing the right resources and leadership to enable both their people and processes to be successful. These two were in a time warp, reacting to failure instead of preparing for success.
The President needs to find a way to get the job done at the Vice President level. He's the one who needs either better people or better processes.