That could be either I reckon, a kerb could easily trip you up as could being a defuser and someone opposes your efforts to defuse an argument.
Personally, and to answer the question you pose. I would rather stay out of it, an argument can turn very volatile or perhaps a lot of feelings could be hurt. Your attempts to defuse could get you involved and taking some blame in some way! Just not worth it as it’s probably not ‘a life or death situation’ anyway.
I agree Baz…if two people start to disagree, then I believe others should stay out of it, as it’s like they are adding more fuel to it…that’s the way I see it anyway.
On saying that though…they could be pot stirring or genuinely trying to diffuse the disagreement before it gets out of hand.
Or they could be pot stirring and trying to draw others into their argument. Then if enough people became involved they could just withdraw and watch the fun. I am sure you know that happens a lot, especially on forums. There is a name for it but that I will refrain from expanding upon.