In this article, it indicates that a bill was passed by the NJ State Assembly and signed into law by the Acting Governor who was the Senate President per the NJ's succession rules. This seemed odd to me, so I also verified that this was the case on Wikipedia, where I learned the Acting Governor signed 3 other bills as well.
The need for an Acting Governor in this case was simply because both the Governor and Lt. Governor were out of state.
For the purposes of this question, let's assume that the Senate President and the Governor are not in agreement on these bills. Could the Senate President, serving as an Acting Governor, sign a bill into law without the approval of the actual Governor if the latter is merely out of state? If so, can the actual Governor reverse the signing once they return to the state?
If not, is the validity of the law subject to judicial scrutiny if it only passed because of the Senate President's vote? In other words, is there some sort of requirement that a bill can't become a law if the person signing it also voted for it? I ask this because given the Senate President's role, it seems they could create scenarios where laws they want are passed expressly when the Governor and Lt. Governor are out of town, thereby ensuring they can quickly sign them before the Governor returns to veto.