"Could it be a coincidence that...?" [It could hardly be an accident that just at the same time as blank, also blank.]
This asserts that a coincidence is not quite a coincidence, but actually a stronger form of correlation or even causation. But it does so covertly, not by demonstrating what is causing what, but simply by relying on the skepticism of the reader, who presumably doesn't believe in coincidences.
"Blank is the general case, and blank is no exception."
This one goes from the general to the specific by asserting that the specific is no exception to the general case. There are more interesting ways of moving from the general to the particular, though. Do we expect this case to be an exception, or not? Is it a particular kind of embodiment of the general case that is noteworthy.
"... does not happen in a vacuum..."
Here the appeal is to context and nuance, but no specific context is invoked. What you really want to say is that the best context for understanding the phenomenon under consideration is this one.
You might want to avoid these particular kinds of reasoning.