Muphry's Law Strikes Again

Mark Liberman over at the Language Log links to a post about spelling rage (warning NSFW words in large type). The post is somewhat humorous, and worth reading but I noticed that it suffers from Muphry's Law. Muphry's Law (not to be confused with Murphy's Law) clearly states that when someone is critiquing spelling, grammar or punctuation they'll inevitably have a spelling, grammar or punctuation mistake in their critique.

Case in point, when talking about commas: "...you always want to put a space after him when you use him a sentence."

That sentence is missing the word 'in'.