You say disgruntled employee, I say it sounds like a problem company.
I just read this and I can say, I worked with a company that was roughly this but multiplied by 0.25. Main product that never worked but sold as if it did? Check. Weird investor schemes? Check. Sales people lying about the product, or the customers (as if the company had them, instead of a string of noncommittal POCs)? Check. Sales people having no clue what the product did, and just selling the bullshit they invented? Check. CEO rotations? Check. Someone getting entangled in what looked like a different version of Nigerian Prince scam? Check.
I can 100% believe everything the author said, because I've seen a lite version of it. And if all you know about a company comes from their website, press, conferences and their salesmen, you'll never realize how rotten things are on the inside.