In this light, I've seen these back-room clerical apps, that need everyone's special requirements included, turn into boondogles of team bloat and mis-communication. If Rick thought he could ship it himself, and had a track record to make the estimate, I can't begrudge mgmt for hoping he could do it, even betting on him. As others have noted, it took a full team a year with scaled back feature set. A losing bet, that could have been played safer for sure, but maybe only wrong in project hind-sight.
From Rick's perspective, I'd speculate he was somewhat motivated by a threat of impending irrelevance, and somewhat justified in estimating the true penalty in his productivity from collaboration. Again, from snooping on the author, I think there was some Oracle, lots of Microsoft in tech stack. Knowing this type of 10x guy, his implementation style is usually somewhat deprecated from a decade of head down productivity. Also, one of the biggest problems outside "real tech stacks" is the lack of collaboration workflows and conventions. So it may indeed have been true that tripling man hours on the project could have resulted in negative productivity given the project's code base 6 months in. I still think Rick earned the right to gamble, fail, and go down with his ship. It was foolish because he would have likely only grown in esteem and compensation with some artful delegation. And doubly foolish, if his stack skills weren't highly marketable; limited upside with huge downside for him. But I find it commendable nonetheless he chose to Build when "Lead" would have been more rewarding; and ultimately if he makes the deadline, no crisis ever comes to head.
Finally, the "Rest of the Team" did what I think was the tough but right decision to move forward. No way can you "reset" the project while sustaining weekly second-guessing coming from an obsessive, knowledgeable, ego-bruised, senior team member. Ultimately, even self proclaimed logical dev's are irrational actors and as susceptible to group dynamics as anyone. We're all limited people: mgmt can't predict the future, proven-shippers sometimes come up short. I don't know if we need to read this as a call to blame.