This reeks of a scam to me. IDK how you'd burn a pipe out in 6 or 7 smokes - especially a Peterson. What's he smoking? Cordite?

I'd guess he's trying to screw you; saying it burned out and hoping you'll just refund the money. Either that or he bought it to use in a speed smoking competition.

I'd make him send it back for sure and hopefully you can verify that it is the pipe you sent and he hasn't switched it out.