Unfortunately, I am not aware of the legal position and procedure in the Pakistan courts. It may be advisable for you to consult some local lawyer in Pakistan who may be well-versed in the laws and procedure applicable in Pakistan, including on the issue of filing a review petition in the high court. Or, please ask this question on some online law forum of Pakistan.
But, if a similar issue had arisen in India, then it would depend on the facts of the case. In India, if a petition can succeed only on a limited number of points then sometimes the courts do not go into the merits of the remaining points. However, from your viewpoint, if it is felt that the remaining point (that has been left unanswered) was so important that it could have changed the direction of the judgment which has been delivered on other two points only, and if it is felt that the remaining point has been mistakenly left answered by the high court, then it would be advisable to file a review petition in the high court; and in such situation, it may be pointed out that there is an error apparent on the face of the record since one important issue has not been covered in the judgment due to which the judgment has become erroneous. However, even in such a situation (and specially in the situation when the remaining issue has been deliberately left unanswered by high court and not mistakenly), one has the option to approach the Supreme Court since after all, the high court has decided the matter finally and all issues left unanswered are supposed to have been rejected, unless mentioned otherwise (such as if the high court specifically mentions that the remaining issue left unanswered is irrelevant for the fate of the case, etc.; it happens in India in certain types of cases, such as in habeas corpus petitions, preventive detention matters, etc., where if the petition succeeds even on one point then other points may not be discussed). The Supreme Court can, then, decide all the issues itself or may decide to remit the case back to the high court to decide the unanswered point on merits.
What I have mentioned above is generally what happens in India in a similar matter. I hope it helps. But, my sincere advice to you would be to consult some local lawyer in Pakistan who may better advise you as per the laws applicable in your country.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.