From My personal experience, please follow my suggestions.

I got this from my personal experience, hope you can follow what i said.

with 99% possibility, the correction action plan is just a middle step to fire your friend. The comany has to estabilish a step by step record to show they are playing fair game to fire the employee. Normally the fire is not based on performance, but on the violation of corporate rule or on breaking the law.

If fired, because of violation of corporate rule, not necessarily breaking law, your friend won't get unemployment benefits. Also if your friend resign, your friend won't get unemployment benefits either. But if your friend resign, your friend won't have bad record when look for the next job. If your friend is fired, your friend will find it very difficult to find a good job. In some area, your friend's future career development could be seriously damaged by the fire record.

So my suggestion is not to take chance. Go to HR, negotiate a lay-off package and leave the company. Your friend can give up the lawsuit right in exchange of the lay-off package. If they agree, your friend can claim unemployment benefits and clean record for next job hunting. If they don't agree, just resign and start job hunting, no unemployment benefits, but your friend can have a clean record to start over again.

Take it seriously before things start to really against your friend.