I’m going to assume Toney is a normal guy on a night out with little real combat/engagement experience, so under that proviso, I would expect proportional response to be low on his list of priorities in a heightened situation where he’s not entirely sure of what is and isn’t a threat to him. Besides, if someone who you haven’t given permission to be in your personal space is in such proximity to be headbutted in the first place, there’s a serious breach of boundaries enough to warrant a panicked response.While I totally agree with the idea of your safety, headbutting someone is rarely ever proportional to that. In general it makes no sense, as you're literally throwing your head towards your potential threat. You only ever headbutt someone to inflict maximum damage, so I think he would have to feel in serious danger to really ever justify it.
On another note, an informed person would strike with something more dangerous in that proximity… a headbutt startles or breaks a nose, it’s better that than an unannounced uppercut or elbow strike to the temple etc. I’d say a headbutt might have the greater short-term showy effect (blood etc.) but the others could potentially cause far more serious harm. I’d also say other strikes show more premeditation (you’re not going to randomly through the aforementioned; they much more informed strikes), so funnily enough, Ivan Toney headbutts someone who is all over him doesn’t sound half as bad as Ivan Toney uppercuts fan!

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