The 4th quarter wasn't about 'adjustments' - the Rams put the ball in Goff's hands - he had time to throw and missed throws or didn't find open receivers. that's it? What magical adjustment did Shanahan make? Mullins made the throws, they ran the ball, they won the game.
Don't make it more complicated than that. Shanahan isn't some master genius or a riddle that McVay can't solve. McVay's scheme had guys open - Goff just missed them.
As many pundits and ex-players and coaches have said - x's and o's are great - but at some point, your star players need to make plays. With the game on the line - get the ball in the hands of your best playmakers and let them make a play.