There are a lot of problems here:
1. 1980's Shotputter
2. Corrupt sports administrators
3. Terrible scientists
To address each problem:
1. Most throwers were / are juiced
2. Most sports administrators were / are corrupt
3. Most lab techs were / are pretty inept
The big question is:
What did Paul Edwards do to get banned? Testing positive is not enough, plenty of opportunity to cover up the positive tests with #2 above.
He obviously rubbed someone high up the wrong way. Perhaps he can comment in this thread about enemies etc. that would want to see him go down like this.
Regarding #3 above, in all likelihood the MS was calibrated properly, the calibration data was either not saved or can be found in someones old dusty lab book either lost or thrown out by now. It's a bit of a weak argument in my opinion, just because they can't find the data doesn't mean they didn't perform the calibration. From my experience in labs, I know most of these guys are fairly useless.