'I still think it's possible to expect children to demonstrate they've learned the rules, such as they are, while encouraging them to think about those rules. You stand a much better chance of challenging any orthodoxy if you understand how it works.'
I think I've already agreed with you on this one. Don't know anyone who doesn't. It's one reason why I became an English teacher and TBH I don't know how you'd cope if you didn't feel this way because you'd be working against your department, school, exam boards and national curriculum.
'If AQA (wasn't there a big scandal about them being crap some time ago, btw?)'
I think you're talking about OCR not marking properly a few years ago.
'does demand correct spelling and grammar, how come people are getting A* while being unable to spell - the original point of the article cited in the OP?'
I think I've already addressed this. You couldn't get an A unless you performed extremely well in your English GCSE exam and coursework. Only a tiny percentage do get A. The vast majority of these students will be good spellers and many will be excellent. However, like Shakespeare, some excellent readers and writers may make a few spelling errors. If exam markers decided that a few spelling errors which did not impede meaning in an otherwise exceptional exam response meant that a student couldn't get an A* they wouldn't be following the mark scheme agreed by QCA and they shouldn't really be examining.
'Btw, don't see how the line that teachers do teach spelling stacks up against the argument that you don't want to correct their mistakes for fear of covering their work in red pen. If you aren't correcting their mistakes, how do they know they've made them?'
Did you read my previous post? Any English teacher who does not 'teach spelling', point out errors and find strategies to help his or her students address these is a very strange creature. I've not met any. I would find it difficult to believe that an English teacher who didn't care or couldn't be bothered to do spelling could exist in any school which follows the National Curriculum. But there may be some weird exceptions.
'There must be a way of encouraging creativity while pointing out factual errors, surely - make margin comments in a different colour for positive points?'
Yes, quite a few ways. As I've said it is more helpful to tackle 1 or 2 errors or patterns or errors in each piece of work than cover a piece of work in red pen randomly without showing a student how to improve or focusing on the bigger things - structure, interest, sentence structure ... Doesn't this make sense to you? If a dyslexic student or any student had made 20+ spelling mistakes in a single piece of work how would it help him or her to cover these in red, orange or purple pen? If that was my work I'd be gutted. If I was the parent of a teacher who did this I'd be livid and I'd wonder why the teacher had such a hang-up over spelling rather than dealing with a piece of work as a whole.