I've noticed that often somebody will assign an issue to themselves, upload a patch, mark it "ready for review", get a review and then not respond to the issue again for weeks or months or ever.
This seems to be especially common for issues tagged with "Novice". It also seems to happen sometimes after a group of people claim a set of related issues at a sprint and forget to clean-up after the sprint is over.
This means that there are a lot of easy to re-roll/fix patches sitting out there that nobody is updating because the issue looks superficially like it is being taken care of.
This is especially misleading with the [#XXXX@] syntax for cross linking issues from a meta issue as you see the names of who is assigned to tasks before you see when the task was last updated.
I think a simple way to help avoid this would be to simply un-assign any issue that hasn't had any activity in 2 weeks. It is very easy for that person to re-assign the issue to themselves if they're still working on it but it will give others the opportunity to pick up patches before they get so stale and far behind HEAD that they need lots of extra work to finish.
I believe this would work in exactly the same way that "fixed" tickets are "closed (fixed)" after a period of time has elapsed.