[josso]

> Taking a better job is fine, but halfway a project it might kill the project when some of the top guys decide to leave. It might even be worse when the architect of the legacy-system decides to leave with knowledge of all the undocumented business rules.

Exactly. The world is pretty small and you shouldn't step on somebody's toes unless you absolutely don't see another way out.

The sensitive thing to do here, is to make sure you've got your ass covered and if this is a persisting problem or you feel like you can't work there anymore, then you quit after the current job is done. And hopefully you can leave with a good recommendation.