Did you include the "sic" as a joke? If so well played my friend, if not the streak continues. Including "sic" is grammatically incorrect because you are not transcribing an error or misspelling something on purpose.
I believe you to be mistaken. I did not include it as a joke, and using "sic" in this context is literally correct. The reference is to "Muphry's" law (carefully note the spelling), and almost everyone would assume that I had mis-spelled that, intending instead "Murphy's" law. Using "sic" indicates that it is written as I intended.
Quoting Wikipedia:
The Latin adverb sic ("thus"; in full:
sic erat scriptum, "thus was it written")
...
The usual purpose is to inform the reader
that any errors or apparent errors in the
transcribed material do not arise from
transcription errors, ...
But others, who do not read as closely as you apparently do, need the extra information provided by the "(sic)". More than once when quoting Muphry's Law I've been "corrected".
