Why dismiss a report by an academic for an independent higher education think tank as biased load of tosh, OP? On what basis do you consider them biased? The analysis is in line with what the Royal Statistical Society already released, and they've gone on to urge UK's Statistics Authority to urgently review both English and Scottish exam authorities.
And, if more teachers had actually estimated more realistic grades, they wouldn’t have needed so much moderation.
I refuse to blame teachers. Either they're the experts in their pupils and should be assigning grades, or they're not and they shouldn't. OFQUAL can't have it both ways. And the reality is that grade inflation will happen anyway, since in October exam series final grade can only stay the same or go up.