Thanks for the input, Margaux and Michael.
To Margaux's response - I believe that the troubling engagement was not with the 'tension bringer' but to the other circle member. I think the 'tension bringer' had clearly stated what they wanted.
To Michael's response - yes I agree and I work to remind tension bringers about their options. I also like the idea about how to prevent 'out of control' conversation through a time-box. I do practice checking in, when we're in 'open response to a request for information or advice' with the 'tension-bringer' with 'is this helping?' and 'would you like to continue?'.
To continue with that tangent - I do notice that sometimes then the individual will reply with a 'yeah, but...' or some other type of further specific engagement. I'm thinking that while a little bit of that may not be harmful, that it's generally a sign that an offline meeting would be more efficient.
Any responses, though, to forceful interruption challenging a Facilitator? If/when and how to respond? I've been wondering if a 'perhaps you have a new tension about my facilitation, let's record that and then get back to <this person>'s tension' might be an approach.