Considering there are people here who have their redline raised (ecutek, OFT) too 8K+ on a stock block. I wouldn't worry too much. I had an over rev once much greater than yours and I laid 172 hp at the wheels the following year, plus I've got almost 45k KM after said incident. I'm not going to say what the number was for fear of warranty getting voided (top 4th ->5th but decided last second I wanted 3rd for a corner - off ramp...whoops). But I also hit the clutch as soon as I realized what happened. I was so worried, like you I babied it home as gentle as possible, listening for anything abnormal. And as said above don't do it again!
