Avila has been a member of the school board for the past 16 years, but, at Thursday's meeting, he was told by the district's attorney that he can not serve on both.
Brent North, an attorney for the school district, told the board that an official can't represent an overlapping area on two government boards.
"I'm afraid by leaving, we are going to go backward," Avila told those in attendance, after speaking at length about his desire not to leave the board.
"I'm not done yet."
It was a statement the outgoing member repeated almost half a dozen times at various moments in the meeting.
"I do not want to go if the right person is not going to be appointed," he said.
At the meeting, the board was given several options to fill the vacancy, including: appoint a successor, hold a special election, or leave the decision up to the San Bernardino County Superintendent of Schools.
The first choice, to order an election, would take place on the next established election date, which can be no less than 130 days from the day of vacancy.
That would mean the special election would likely be held June 4.
The other option would be for the board to appoint a successor to fill the post until the next election, which
But North said the newly elected board members would make the decision, not the person who has resigned.
Once there is a vacancy and if the board elects to appoint the successor, North told them they would need to make that process as transparent as possible.
The board would not be allowed to talk about the candidates or interview them in closed session.
"That discussion remains to be in open session," North said.
Avila repeatedly questioned the process.
At one point during the meeting, he asked whether the board would be able to review the candidates applications or interview them in closed session.
North told them it was not an option.
Avila seemed confused about the process, referring to how the district had handled it in the past.
Eventually, he told those in attendance that he would only be in favor of a public process, and warned them that they should also be very concerned.
"I sense there is a movement to appoint one particular person that does not have the mandate of the community," Avila said.
"I'd rather see a special election and let you guys decide. Whatever happens, I'll accept that because it comes from the mandate of you, not one or two people. You will benefit from that."
The board decided to leave that decision for its next meeting on Dec. 13.
By then, Avila is expected to already begin his term as an Ontario councilman.
The council will meet Dec. 4 and he is expected to be sworn in then.
Once Avila is sworn in as a council member, he automatically loses his post with the school district.
"I'm not done yet with this school board - not until I'm satisfied with who is going to be appointed. Children are more important to me," he said.
Outgoing board president, Sam Crowe, who lost his reelection bid, said he felt some of Avila's comments were indirectly meant for him. But Crowe said it is highly unlikely that he will be seeking to fill the vacancy.
"I've avoided any kind of conversations (about the successor) because you have to let the board decide," he said.
Crowe said he is not sure if Avila will attempt to stay on the school board for the next meeting, since he has yet to turn in his resignation.
As the two accepted a recognition plaque for their service from the district, Avila once again brought up the topic of the possible vacancy. He alluded to what action he was going to take.
"I really don't know what I'm going to do. I do, but because of strategy reasons and people listening, I'm not going to tell you want I'm going to do. But I'm going to get what I want," Avila said.