I came up with 3-4 months because the question was never actually answered, so I made up my own timeframe based on the typical complaint from someone who has been denied a return based on how long it's been since they purchased an item.
And, you are correct that what I would have done myself isn't necessarily relevant, but that's more because I would never have bought HDMI cables at Best Buy in the first place. Never have, never will. And I almost always have a stash of extra HDMI, optical, and RCA cables on hand in my house "just in case" a cable goes bad, I need to rearrange equipment and need a different length, or a friend gets a new piece of equipment and doesn't have the right cables themselves.
So, in that respect, since I don't buy cables at Best Buy, and since I keep spare cables around my house, you are correct, what I would do is irrelevant to what you did, just he same as my average of less than 4 posts per day on the boards is irrelevant as to my affiliations.
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*disclaimer* I am not now, nor have I ever been, an employee of Best Buy, Geek Squad, nor of any of their affiliate, parent, or subsidiary companies.