I'm a fairly fast few-fingered typist, but I have a tendency to type pairs of letters in reverse order. Usually these typos are painfully obvious, but recently I looked in puzzlement at a comment I had written in my program:
/* find the desired time. */
The comment made no sense in context. Reading the code carefully, I corrected it to:
/* find the desired item. */
Two reverse letter-pairs in a row, creating a genuine word. Now that’s a record (fro em, anyway)!