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.
Unfortunately, unless you signed a contract of employment that expressly states that you can only be suspended or terminated for cause, your employment is "at will." At will employees can legally be suspended at any time and they don't have to meet any particular burden of proof to do so. There is no due process requirement.
Your only recourse would be to file for unemployment during the suspension, forcing the employer to legally justify the suspension enough to block your unemployment during it.
I will state though that when it comes to the term "insubordination" or being disrespectful, it only works in one direction...lower ranked to higher ranked. So, while he certainly may have been factually disrespectful to you, legally speaking it wouldn't matter.
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.