Mike, who is researching the Ginn family in Hertfordshire (see his blog the blog www.Ginn-hertfordshire.blogspot.co.uk) has drawn my attention to a case history on the excellent Herts Past Policing web site.
A saying at the time was "A wife, a dog, and a walnut tree - the more you beat them the better they be." and clearly Walter hit Alice too hard ...The Policing web site quotes the contemporary newspaper accounts in detail and it would seem that both the all male coroner's jury, and the one trying Walter, took it for granted that a husband could normally hit his wife - and Walter was only convicted of unlawful wounding - despite the fact that the wound was fatal! As a result he had a comparatively minor sentence and went to Canada after being released from prison.