> the definition of a particular offense (Grievous Bodily Harm, say) is a matter of law This isn't strictly true - s.18 (GBH) requires intent, which is a quest

> the definition of a particular offense (Grievous Bodily Harm, say) is a matter of law This isn't strictly true - s.18 (GBH) requires intent, which is a question for the jury. Furthermore, what constitutes "really serious" injury is a question for the jury. You can break in down into questions of fact (e.g. Did the defendant have intent? Did the defendant cause these injuries? Are these injuries "really serious"?), but it's not as clear cut as did the defendant throw the punch (they must judge if they consider the injuries to be "really serious", which isn't quite a question of fact). In addition, juries are entitled to make a decision based on their conscience, per Bushel's case.