foul shot or not

[mojo1936]

on a free ball stuation the object ball is the yellow you take the green ball as a free ball if hitting the green the yellow goes down but also the green goes down is this a foul shot ? or do you score 4 points and the green comes back up and respotted

[RGCirencester]

When given a free ball on a red, and you pot both the free ball and a red, you score a point for each ball are now on a colour (as if you had potted two reds). When no reds are left on the table you only score the points for the current colour on, regardless of if you pot the free ball, the ball on or both.
So assuming you hit the nominated free ball first (in this case the green), and potted both the yellow and the green you would score 2 points, the green gets respotted and the ball on is now the green.