That kind of tactic is metagamey, cowardly, possibly suicidal, and it is hard to imagine any sane person ever doing such a thing. It is also comedy
gold, and, if I were there to witness it, I would have laughed like crazy upon watching someone do such a thing. Since the first few issues are trivial at best, and comedy is pretty much half the point of D&D, I would say that the move was pure genius.
For just a moment, regardless of how he was portrayed previously, your character became a classic "cowardly buffoon" character, the kind that entertains everyone by doing really off-the-wall things during fits of pure panic in the middle of dangerous situations. This kind of character is stock trope of almost all human storytelling, so I applaud your introduction of such things into a game of D&D, even if it may have been unintentional. Actually, characters like that tend to be overly-analytical and genre-savvy, so it would be almost in character for such a character to use metagame knowledge.
Honestly, I could almost swear I have seen a cowardly character knock himself unconscious out of fear (accidentally or not) in one anime or another at some time... It seems like the kind of thing Usopp from One Piece would do...