The first angle am looking at it is to define the terms "running mate" and "ticket". According to Wikipedia, a running mate is a person running together with another person on a joint ticket during an election.
According to Wikipedia again, A ticket refers to a single election choice which fills more than one political office or seat. For example, in the U.S., the candidates for President and Vice President run on the same "ticket", because they are elected together on a single ballot question rather than separately.
This means that during an election, the voters are casting their votes for the entire ticket and not just for the individual. Logically, what this means is that if one candidate dies or is incapacitated, the ticket still remains valid.

However, Section 187(1) of the Nigerian constitution states: “In any election to which the foregoing provisions of this part of this Chapter, a candidate for the office of Governor of a State shall not be deemed to have been validly nominated for such office unless he nominates another candidate as his associate for his running for the office of Governor, who is to occupy the office of Deputy Governor; and that candidate shall be deemed to have been duly elected to the office of Deputy Governor if the candidate who nominated him is duly elected as Governor in accordance with the said provisions.”
A close look at the last sentence in that section means that there can only be a deputy governor if the governorship candidate has being duely elected. Meaning if the governorship candidate was not elected, there can't be a deputy governor. It thus appear that the deputy governorship candidate is simply an appendage of the governorship candidate and he only becomes legally activate only when the governorship candidate is elected and not before. In other words, the electoral provisions does not really recognize the deputy governorship candidate until the governorship candidate is elected. That is when the deputy governorship candidate becomes a legal entity. I want to believe this is because the deputy governorship candidate was not picked through the primaries (an election process) and was simply picked by the governorship candidate. What this literally means is that the deputy governorship candidate is simply an individual and would only be able to take the place of the governor legally when the latter is elected.

Looking closely at the two submissions, I am of the opinion that the argument might favor the APC and INEC in their choices of not recognizing James Faleke as the governorship candidate of the APC after Audu's death. This is because he was not produced through the primaries which is the only vehicle recognized under the law and he does not have a legal status in the electoral ecosystem yet until his governorship candidate has a mandate. If APC has choosen another deputy governorship candidate for Bello, it will still have being in order.

Nice analysis... But the law is like a 2 edged sword.

By our laws, Falake has no case against either the party or INEC. He would have had a case if, and only if the elections had been declared conclusive and Audu the winner. My advise to him is to accept party position and stop being unnecessarily critical of his party. By the way...I thought Tinubu was an advocate of party supremacy...why can't Tinubu call this his boy to order....saraki Will find this very interesting.

nice. but bello too hasn't met some constitutional requirements also. the law says the acceptable candidates must have been chosen through an inec supervised primaries, must have actively participated in the party campaigns and must have a running mate. now he didn't meet these, which is why faleke and wada are making noise. rumours had it the bello worked against audu's victory. right now, he isn't on a joint ticket as faleke had written to inec on this issue. and by law, a 30 day period is given for the replacement of any candidate so as to meet these requirements.