Personally I'd tweak your last sentence to "return statements in the middle of a function."

Early returns at the very top for things like None if you pass in an Option type don't increase the risk of bugs, but if you have a return nested somewhere in the middle it makes it easier to either write bugs up front or especially have bugs created during a refactor. I certainly have had cases where returns in the middle of a beefy function caused me headaches when trying to add functionality.