I'd probably not have ruined my roll of film over someone yelling at me without me having got one word through. After a few tries of not having been able to respond, I'd've started shouting back, most likely. I've gotten into arguments (and being close to getting in fights over being right) while walking around (though not camera related, yet), and it's usually possible to at least defuse the situation as long as the other party listens to what you're saying. We probably have about the same kind of personality, going by your post, but I feel you could've probably gotten through to him without wasting the roll.
I must say the interface of the blog is infuriatingly hard to navigate, it took minutes of clicking around to even find the comments. I recognize the sentiment from the comment I think you were talking about though, and it's not an uncommon one, unfortunately.