"a good man was just in the wrong place at the wrong time "
yeh what a great bloke - has a knife on him and he's prepared to use it !!
With that in mind re-read this section of Chris's post :
Section 18 GBH carries a maximum sentence of life imprisonment. If your partner used a glass to inflict the injury, the sentencing guidelines suggest a sentence of 3 years imprisonment. If he used a knife, the guidelines recommend a sentence in the range 3 to 8 years:
http://www.sentencing-guidelines.gov.uk/guidel ines/other/courtappeal/default.asp?T=Cases&cat ID=3&subject=WOUNDING%20/%20CAUSING%20GRIEVOUS %20BODILY%20HARM%20WITH%20INTENT
I think he's lucky not to be looking at a murder charge - it could have ended so differently.