Since the "rules of the Internet" are not really a single list (other than Rule 34, which tends to remain constant in all variations), you should really specify which "Rule 43" you mean. There's "You can find anything on the Internet if you are willing to look for it long enough" and "It is a delicious trap. You must hit it", both of which are also Rule 43 on their respective "Rules of the Internet" lists (and are not the only such lists - Urban Dictionary has its own, with a much cruder Rule 43 that I won't copy here, as well as another 4chan site, with its own crude Rule 43 replacing the "delicious trap" one).
But I suspect the one meant here is "The more beautiful and pure a thing is, the more satisfying it is to corrupt it", which certainly applies to the situation in that thread.