I’d say your lesson(and most others) make an improvement to your setup or efficiency of strike - which should see an immediate improvement- but a true swing change(in terms of path/position) takes ages to drill in and become your actual swing. That’s what the pro was talking about.
To me that's a classic tunneling action which would see the real impact being to the back or head as opposed to causing a lower body impact that would threaten that part of the body.
I really think you are taking things too far - the impact on Elliott was unfortunate, but it wont be something...