So I've been trying to get at least one full unbroken season from D (owing to intermittent truncation) and hit the token bucket limit... After waiting the requisite time, and attempting to re-download the same file on which the token bucket got drained, AS errored out with "Could not delete existing file."
It seems AS is forgetting to close the file.
Restarting AS resolves the problem.
It seems AS is forgetting to close the file.
Restarting AS resolves the problem.