Regardless of the outcome of this incident, if you apply to Y Combinator with someone who knows the YC partners better than you, and your cofounder decides to push you out, your cofounder will be supported by YC against you. This is now something that every team of founders will have to think harder about now. It will harm founder cohesion which will reduce the success percentage in each batch.
On the other hand, this is a positive signal to people who want to exploit a cofounder to get past the YC application process and then push them out of the company.