Don't know if it's possible, but some sort of restriction on closing a UR that has a conversation you're not involved in may be useful.
As it stands now: an error is reported. Editor A initiates a conversation for more information. Editor B comes along X period of time later, [doesn't read the conversation, can't figure out what's wrong,]
marks it as not identified, and that's it unless the original reporter takes the time to report it again.
With the restriction enacted, Editor B can't close the report until Y period of time later unless certain conditions are met (they're AM/CM/staff, the report has been open for more than Z days, etc). Even if Editor B adds something to the conversation, there would still be a period of time before they can close it.
Just a rough idea that came to mind after having more than a couple URs closed out as not identified within a few hours of starting a conversation by some overly-enthusiastic