There's no law against his going back and so there shouldn't be. If the club makes moves to reinstate him, my guess is that public outrage will stop them short. That would be no bad thing in m'humble. They should heed the cautionary tale of Liverpool players donning those extremely ill-advised t-shirts in support of Luis Suarez when he was facing his racist abuse rap. The club have spent the last couple of years wishing they'd had more bloody sense.