True, but my emphasis is on the post-hoc nature of the act. Looking up words before sending the note is so pedestrian; I was trying to succinctly capture the act of looking up the word after it is too late to correct.
I just have to share my favorite malapropism here: At a small social gathering the wife of my friend was trying to find either the word "ravenous" or "famished" but instead went on for some time that she was "ravished, absolutely ravished." She liked to say things in a dramatic way, which really skewed the interpretation of her narrative to the more salacious meanings of the word. It was fun watching her husband, who was torn between correcting her or saying nothing, hoping that the topic would die a natural death.
I learned from her eventual embarassment, so needless to say, I have always used "ravished" correctly in my personal communications since then. :-)