Pretty much on the money.
Nothing wrong with using a weapon if they don't though, all it does is factor into the 'reasonable force' concept. A concept which wasn't defined in legislation and, despite how long it has been around, it is still subject to new and changing case law judgements.
5ft 3ins, 9 stone woman .vs. 6ft, 13 stone bloke... reasonable force could be stretched quite far.
The key is stopping when the threat is no longer there.
I keep baby oil and viagra to hand in case of burglars. Would you want to fight a naked oiled up dude who looks happy to see you?
an give them a good seeing too? ooohhh eerrrrr