Oh dear. You actually copped a 2 stroke penalty (unless your ball was on the putting green) which is all the more annoying for you since you were right in the first place.
As you thought, you should have replaced with a one stroke penalty. Because you didn't, you played from a wrong place and that cost you a two stroke penalty.
As well as the situations in which there is no penalty for causing your ball to move already mentioned, you can add accidentally moving your ball when searching for it.
And I should add that in the teeing area, there is no penalty provided your ball is not yet in play.
Thank you, fortunately for me it was not me who did this.
However the rule the person who did strike the ball cited was that there was no intention to play a shot therefore it did not count as a penalty as the impact was accidental. So no stroke was played. I am unaware of the rule number but apparently it is stated around the basis of intent.
Neither myself or the third Player in our group knew the rule other than our belief it was a penalty.
But I would ask, anyone heard of this ‘Intent’ point before
To me, unless accidentally moved in a search any action which moves a ball in play other than on a green intentionally or not is a penalty and the ball needs to be replaced. Though I maybe wrong here.
Would add, in a good few years of playing this is the first time I have seen this happen.