As usual, I'm beginning to see another side to this.
Initially I wanted shot of both players for disrespecting the Manager, not for disrespecting Murty. Our Manager has to be accorded respect, not 'piled onto', whoever is in the role.
However, reading Miller's pov where he specifically states that Murty was not present at the time of his involvement I may be about to do a 180.
If Murty decided that there would be no post-mortem/discussion/review until much later(his "it's too raw at the moment" comment) and and Miller interpreted that as there would be no managerial p-m and then took that as carte-blanch to, as senior-pro and vice-captain, lay into the players for disgracing the club - I don't see much, if any, issue.
And, if the above is what happened and Murty went to Robertson not because he was verbally assaulted but because Miller disobeyed Murty's touchy-feely approach then Murty for raising it and Robertson for acting on it need rooted out, pronto.