If you open up a dictionary and look at the definition of proportionality, it really speaks to a direct and limited relationship between two separate things. This is where these two things are proportional to each other. It doesn't allow for plus or minus five degrees or ten degrees. That's where the courts have said that proportionality between the threat you're trying to avoid and the harm you cause is obviously a guiding principle. We don't want to allow people to shoot others just because they're at risk of having a finger broken.
So there's no question that it's extremely important. This goes back to a decision from the House of Lords called Palmer, which I think dates from the early 1970s, that has driven the rest of the case law in this area throughout the common law world. It's almost an error of law for the court not to instruct the jury to apply proportionality, not in a rigid manner but to apply it in a flexible, tolerant manner.
In other words, if someone in a situation of heightened passion, where they're fearful for their lives, inflicts more harm than was absolutely necessary, you should still consider whether what they did was reasonable based on their fear, based on the heightened tension of the situation, based on the crisis mode they were in. You should give them that latitude. And the jury should not be told to find exactly how much force was proportional to the threat and no more. They're really told to come at it with much more generosity to the situation that the accused was in.