This is how it usually goes.
We're on break during a meeting or strategy session. A participant pulls me aside and expresses concern about something that is happening in the group, something he thinks I as the external facilitator need to take care of when we regroup.
I listen attentively, thank the participant for sharing his perspective, and invite him to raise it with the group when we reconvene. Typically, he looks at me in mild shock as if to say "You don't think I'm going to bring this up, do you?"
Well yes, I do.
When we are members of a group or participants in a meeting and we see the opportunity to enhance the work we are doing together, it is our responsibility to share that in an appropriate manner. Passing off this responsibility to an external facilitator is at best inappropriate and at worst manipulative. Attempting to do so essentially is saying, "Look there's some stuff going on in the group that I don't like and I want taken care of, but I'm not about to do that. You're the outsider here and you'll be gone tomorrow, so could you just go in and say what I think needs to be said since of course my motives are completely pure and my perspective 100% accurate?"
Not. Going. To happen.
Is it easier for an outsider to share an observation that may be difficult for members of a group to handle? Perhaps, but not if it is an observation the facilitator him/herself does not own. Is it effective? Maybe in the moment. But in the long run members of groups and teams have to learn how to share their perspectives with each other and respond accordingly. And yes, that often can require challenging or somewhat uncomfortable conversations.
So if we don't want to take initiative to address a behavior or issue we think could help our team function more effectively, that's certainly an option available. But doing so makes us enabling, not innocent, bystanders. Let's not pretend otherwise.