right. Dick Fosbury is the Babe Ruth of track and field. He started using a new technique and changed the sport (of high jumping).
For Bolt, time will tell. It appears as though tests are getting stronger and may outlast Bolt's career before the next drug comes along. If Bolt never approaches 9.58 again (or even sub 9.7) then his times are less credible.
One theory is that 9.58 is not beyond human capability (cleanly). We would have gotten there eventually. Bolt just shot out, like a man from the future, to advance the record much quicker than we would expect. A la Bob Beamon. The world caught up to Beamon 23 odd years later. The old LJ WR has been broken by 60 or so people.
Is Bolt ahead of the curve? We will see. The next fastest non-doped time is 9.78 (maybe). Or it could be 9.84. So we will have to wait. If people start breaking those times, and gradually catching up to Bolt of the next 20-40 years until eventually breaking his record, then I might eventually believe it. Assuming that all of them are clean, too!