If that's the only one you've found so far, consider yourself VERY lucky,....I wouldn't worry about it....atleast for now anyway,....keep an eye on it,...if it starts to get any worse, you could have it fixed over the winter, but crax in that area will only reappear over time anyway, and more than likely, they'll be worse the second time around!! If you thought it was a "hair", then it sounds like a clear coat crack,...those are VERY COMMON!!..
A crack that goes down into the gel is more serious. Sounds like yours is a clear coat........not to worry!!
Just my .02
Mac