Match play golf - alternate shot format. Opponents mistakenly pick up my provisional ball. What is ruling?

Question

We were playing Match Play - Alternate Shot format. Player 1 hit tee shot into woods. Player 2 must hit the provisional which is in the fairway. Player 1 declares that he has found his ball and our opponents pick up the provisional in the fairway. However, the ball Player 1 found was not his and first ball is lost.

We replaced the provisional as close to the spot as possible, lying 3, and played out the hole. Was this correct? Do our opponents incur any penalty in match play?

Answer 1

The opponents do not incur a penalty since it was player #1 whose statement percipitated the picking up of the provisional ball. Had he kept quiet until  a positive identification was made, there would have been no dispute. And if you called the opponent for doing so, you would gain an unenviable reputation at our club.

Answer 2

Without consulting the Rules book or decisions on the rules I believe you did the right thing.  It was not your opponents fault that they picked up the provisional.  Player 1 didn't properly identify the ball he found, and when he said he had found it, they were just being courteous picking up the provisional.

Answer 3

I would say that you acted correctly. The opponents acted in good faith, thinking you had found your original ball. They were just trying to keep the round moving.

I couldn't find anything in the decisions that exactly matched this scenario.

Decision 18-3b/4 covers a similar situation. It addresses a caddy picking up the original ball by mistake, thinking it was an abandoned ball:

"Rule 18-3b does not contemplate an opponent or his caddie moving a player’s ball in such circumstances. In equity (Rule 1-4), the ball must be replaced without penalty to anyone."

I think the same principle applies here.