As a beginner, I've found this thread very educational. Thanks!
I'd personally try to correct a senior only if I was concerned a technique would be injurious if applied to me, them, or to someone else.
Even then, I'd phrase my concern in a question, as opposed to a statement.
If I'm wrong, which I think has happened maybe once or twice in my life
,at least I was erring on the side of caution.