[יב] "וישמע משה וייטב בעיניו" -- הודה מיד ולא בוש לאמר "לא שמעתי".
אמר רבי יהודה, חנניה בן יהודה היה דורש כל ימיו: קשה הקפדה שגרמה לו למשה לטעות.
אחר מיתתו הריני משיב על דבריו: ומי גרם לו שהקפיד?! אלא שטעה!
It's an interesting way of looking at anger (הקפדה). Chananya sees Moshe's הקפדה as stemming from an innate angry disposition, an instinctive response of opposing and lashing out -- hence being led to make a mistake in judgement. An "angry man".
R' Yehuda on the other hand sees Moshe's reponse as a resultant by-product of a mistake in judgement. Because I deem this is the way reality ought to be -- I therefore am upset at the fact that it's not. A perfectly valid response -- if only you were right in your thinking. If only your turth was aligned with the Truth that reality ought to be that way. In this particular case it was not and hence in this particular case he was wrong. But Moshe's being a קפדן here then is only tangential to the issue. It's a byproduct of a mistake in comprehension, not a cause. A man who happens to be angry.
