I believe that to be the case. I also think it's pretty obvious that "mom" was dead set against her son entering the service -- and re-upping later. So I wouldn't be at all surprised if she and Casey were somewhat, if not totally, estranged while he was in the service.
I think what we are seeing from her now is an opportunity to use his death to further her cause and if it had been her son she would have used someone elses.
I do not believe we are seeing grief here maybe some guilt if as we both suspect they were estranged and probably had been since he became an adult with obviously completely differing views than hers.
I'm so pleased to see that you think that Casey went into the service to get away from Mom.
I voiced that opinion on a thread the other day and killed the thread.
Glad I'm not alone in my opinion.