Thank you for trusting your question to JA today. I am a licensed attorney with over a decade of law practice and over 20 years of experience in the legal field. I’m happy to be of assistance.
You could sue the COO for hitting you, which is called assault and battery in tort law, but unless you sustained a medical injury there is likely not going to be a financially good reason to do so. You'd end up costing yourself more money in the suit than you'd make in the suit.
In terms of employment law, unless you had a contract of employment that expressly stated you could only be terminated for cause, your employment was "at will" and could legally be terminated at any time. The reason for your termination here, while silly, isn't illegal.
Your comments concerning your mother's release, while completely understandable, were not legally protected comments. This is because the employer's decision to release your mother was actually legal. When one gives a two week notice, what you are actually doing is immediately resigning and then offering the employer the option of having you work for the remaining notice period. The employer doesn't have to accept that notice period and refusing it does not convert the resignation into a termination. Regrettably, that would mean that your termination was not illegal retaliation, because you were not making a complaint about an illegal activity. As such, your termination would be legal.
If you have any further questions, please let me know. I invite follow up questions, so use REPLY for those. If you have no further questions then good luck going forward and please do not forget to rate my service with a top-three rating so that I receive credit for working with you today. Please rate me based on my service and not on your satisfaction with the law, which I am not in control of and I am just reporting to you. Also, feel free to request me in the future, if you have questions concerning a different matter.