The situation of correcting someone else's English is socially awkward, not least because the person doing the correcting usually gets it slightly wrong themselves. It's much better, in my opinion, if corrections are something that's done in private by editors (and if it's oral and thus can't be edited, I'm... nonplussed by the possibility of mistakes). However, even somewhat reputable publications in the Anglosphere rarely have that kind of rigour in their editing, so I think we're doomed to an accelerated level of change in the English language. At least that gives us linguistics enthusiasts more to talk about :)