TwoThouSevHun: Basically no rating was correct at the time. With the old system it you earned the same points when the rating difference between you and your opponent was any number between -399 and +399.
Now the rating calculation is 100% correct according to the definition given. I checked it.
If the recalculation made a so high difference to your rating, it meant that you had somehow profited a lot of the calculation errors, without knowing it.
Don't forget that your opponents ratings were wrong too. For instance you may remember having won a lot of games against a 2200 opponent while he should in fact have been rated 1900 at that time.
About continuity : of course Fencer could very well have said nothing about the error, and just corrected it without recalculating the ratings. Then the ratings would have slowly evolved towards the correct values. But wasn't it fairer to openly admit the mistake and to correct it completely ? Who really wants an undue rating ?