If this action scares other people like Jeremy away from YC companies, that would be wonderful :)
The post never explained what his contributions were or were not. If there was any amount of work done prior to any equity agreements being in place I fail to see how, legally or morally, he would not have at least some piece of the company.
If I recall correctly, every company that goes through YC have cliffs built into their legal documents - or must have them built in when the program commences - for both founders and employees.
Shareholders' agreements and other contracts (such as those with early consultants and employees, like Jeremy Guillory with Cruise) are meant to protect against this uncertainty. Simply ensuring that there's a clear exit strategy for the founders can ease possible tensions before they arise just through the knowledge that they exist. And if things do go south, it ensures that an exit is as painless as possible for all involved.
If you assume things are going to go smoothly, at some point, you're going to be in for a very painful surprise. You should always figure out an exit strategy. Anything less is just dancing on the edge of the volcano.
In the end, you're just buying out their equity in the company at the time of the sale. Nobody really comes out "ahead." But because nobody really knows how they could arrive at that situation, it's important to ensure that your likely contingencies are covered and that the actual process is clearly defined. For instance, you want to make damned certain that someone can't come back for a second bite at the apple after the fact. Even if their claim is specious, it will still derail a deal.
0. http://www.americanbar.org/content/dam/aba/events/real_prope...
Anyway I do believe that by this being so public it will encourage at least some founders to consider proper paperwork early on.