Originally Posted by chewie
you could possibly bent some valves
Not by over-revving alone.
Besides, you'd immediately notice the lack of power and terrible idle lope of a dropped valve or a valve that doesnt seat properly.
You did the right thing by de-clutching as soon as possible. If the clutch engagement on the mis-shift was fairly gentle, you're fine. You may have taken 1500 miles or so off of the clutch's life, but that's small potatoes.
Just don't do it again.