The only lesson to be learned from all of this is when you build your next company, don't allow these people in. I'll keep beating that drum to eternity, because I saw first-hand how the work of tech people is leeched off by so many.
Everyone should be focused on the shared goal of the startup being successful.
What you're working on is triaged constantly, with everyone contributing what they can, learning as necessary.
Everybody wins, or everybody loses. And if you don't work together as a team, it's probably the latter.
(These are not just empty platitudes. For example, when I say everybody wins, that means I expect everyone to have meaningful equity shares -- not a successful exit makes the founders filthy rich, while everyone else gets a small consolation prize for contributing.)
Behind the anecdote, there were unusual and complicated reasons that someone felt and did some things as they did. I tried to carve out a standalone piece for HN, without getting into the more sensitive and irrelevant stuff.
If you don't value your developers perspective in the sales cycle, you are fundamentally doing something wrong. Developer's don't necessarily hold more product knowledge than anyone else, but they sure as shit can tell you how your company can make an extra 100k on a sale by just adding 10 more lines of code.
Sales are incentivized to sell, developers are incentivized to provide impact. Include them.
I can say, from experience:
1. Everything gets better the more technical people are involved with customers. Sales, biz dev, tech supp, trade shows, etc. Probably not as the point person, probably not solo, but mosdef involved. And not every tech has the aptitude, or desire, to be customer facing. YMMV. Still, conversations are shorter, more productive. Customers respond very well. It's been a huge win-win, every time.
2. It's always been hard to convince (commission driven) sales people to loop in techs. It's two separate cultures. eg Upon success, sales person gets a new Porsche and the tech gets more work. Which causes resentment. I don't begrudge high rewards for sales (it's a tough gig). But some perks for the grunts would be nice too. Just saying.