To me, in the case of, say, a mining project, which is largely the jurisdiction of provinces when there's an environmental assessment being conducted, if there's some minor trigger--a small component of the project requires a fisheries authorization--it doesn't make a lot of sense to use that as a basis for requiring an environmental assessment that duplicates the provincial process.
This is particularly problematic because before the Red Chris Supreme Court decision, the federal government was implementing a policy of doing intelligence scoping and not duplicating other mandates. That was rubbed out by the Supreme Court decision.
Basically, what it points out is that the legislation's flawed in this regard. It entrenches duplication, and that's a real problem.