Yeah I had that happen once also on my way to get some cigarettes lol. I borrowed a pair of pliers from the friendly folks at the store and tightened it back on the best I could. It was a loud trip home never the less.
All gasket paper I used for high heat places said it was for high heat. Maybe I over looked it on the listing but I did not see where it said. If it is working that is all that matters. How much run time do you have on the gasket. Just curus.
Only about 25-30 miles. Just noticed the leak yesterday after a quick check. I've had this gasket on since the little mishap on my trip to the Marlboro man lol.