My understanding is that Sickles moved from an assigned position without getting permission to do so. That would make him insubordinate at best I would think.
The move also opened a gap in the lines between his corp and Hancock's 2nd. Whether or not he was correct, and I think not, isn't germane to the question.
If stupid was a criminal offense Sea Lion believers would be doing life.
Shouting out to Half Pint for bringing back the big mugs!