as Sidi mentioned, it really depends on which was the original recommendation, the reasons why you decided to change it and how you communicated the change.
Sometimes the interviewer may challenge you with information which is not relevant, simply to see how you react under pressure – in this case, you may want to stick to your current conclusion.
On the other hand, if there are some relevant data you overlook which clearly point out to a different conclusion, changing it is the correct thing to do. This should be made in the correct way in terms of communication, to show you can properly communicate in front of a client.
Let’s say for example your initial conclusion was not to enter the market and found some clear evidence in the Q&A that changed your reasoning on that. Below are two examples of how you could communicate it.
BAD EXAMPLE: “Seems my conclusion is not correct. I would thus recommend to enter the market instead”.
GOOD EXAMPLE: “I believe the information you underlined added some relevant elements we should consider. On the basis of this, and given our objective to increase profits, I would like to update my initial conclusion, and consider entering the market for the following reasons: Number 1..; Number 2…; Number 3… . To confirm such suggestion, we should however also analyze the competition, which has not been included so far in the analysis and which we may review in the next few days.”
Hope this helps,