He may have a point, but again must like the rest of the shit you read on here, it's pure speculation.
Has GSP used? Fucked if I or anyone else knows but he has tested clean his entire career and is now trying to clean up the sport with improved testing. He has never requested a lifetime ban. All he has asked for is more comprehensive testing, something the sport needs severely as evident by the recent string of hot-piss tests.
I do enjoy reading all the false-accusations being thrown around with his name though. Just proves even further that he is one of the best Champions to ever grace the sport.