To rather stubbornly stick to the drum that I am banging...!!! 
The 'technical guide' seems to say that is ^does" go by sex by default, but then titles the tables gender conflating the two, but then reading down further, its clear that due to "the range of recording practises" throughout the system really no one actually knows what is identity or sex so its all a bloody irresponsible mess :(
the technical guide says:
"'Sex' can be considered to refer to whether someone is male or female based on their physiology, with ‘gender’ representing a social construct or sense of self that takes a wider range of forms. Throughout this report we refer to sex rather than gender, because the binary classification better reflects how individuals are generally reported or managed through the CJS. For example, prisons are either male or
female institutions, with prisoners normally placed based on their legally recognised gender. However, given the range of recording practises (see technical guide for details) throughout the CJS, it is likely that most recording includes a mixture of physiological and personal identity. (Similarly, we refer to females / males and women / men interchangeably in this report, as a reflection of the binary classification in use.) my bold
Individuals with an unknown or not stated sex are not included in the analysis, because it is impossible to tell where they should be counted. High levels of missing sex data would be of concern, both in terms of sample sizes and the risk of systematic bias. To allow users to assess the confidence they have in the data we are using, levels of missing or unreported sex data are reported throughout."
Dereliction of duty springs to my mind and not giving enough of a fuck. Its very difficult to unpick it all.
On topic... The attackers were so bloody persistent too. Not even a wild frenzy and over, but consistently coming back to give more. It really looked like they were tyring to finish him off :(