The most common and most likely answer to this crossword clue is the 3 plus 7 letter word FAT FINGERS
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Buddy explains!
The straight part
We know that "facetious excuse for typo in text" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case facetious excuse for typo in text = fat fingers.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does FAT FINGERS mean?
FAT FINGERS verb- To type (something) erroneously on a keyboard, keypad, or touchscreen by accidentally pressing with a finger one or more keys other than the intended one.