A relief for cause over this is a stretch based on the information you provided me. Now a bad bullet or a reduced rating highly probable.
This is a case of be careful what you ask for….you might get it. Keep in mind your leaders are trying to manage critical resources. when you sign up for something they expect you to follow through. Special units in my experience don’t really get to involved with the family issue part of Soldier. Agree with it or not Mission comes first and some times that has consequences for the family.
While I may not necessary agree with the way you stated your SGM responded I can see his position. Unfortunately some senior leaders also fail to understand the value of a little compassion and empathy.
You might want to try and have a more professional conversation with the CSM and see if the two of you can reach an understanding without emotions involved. You could have caught him on a bad day or he may have gone out on a limb for you and now feels betrayed. Either way you might want to try and mend this fence and remain calm and professional.