I wouldn't recommend doing it too often... if you'd dropped it in 1st would have been a disaster. But going into the red won't damage the engine (especially not just once). And 7800 isn't really that high when I get annoyed.
Cannot beat a screaming vtec smacking off the limiter
Would it be very clear if I had bent a valve or damaged something ? or am I just other thinking it too much and worrying for nothing ?