Shane Logan also rejected criticism that the two players, whose contracts were revoked at the weekend, had been effectively hung out to dry by their club and country.
Mr Logan, who has refused to quit his position as chief executive, said he believed both men had made a “serious mistake” but he hoped they would have success elsewhere.
He said: “They have done a lot for Ulster and Irish Rugby.
“They have made a very serious mistake.
“I hope that they will learn from that and I hope they fulfil their potential going forward.”
Jackson, 26, and his 25-year-old team mate Olding were found not guilty of raping the same woman in June 2016.
Jackson was also unanimously acquitted of sexual assault.
Mr Logan said he did not believe they would ever play for Ireland or Ulster again.
The high-profile trial which ran for nine weeks at Belfast Crown Court brought to light a number of sexually explicit and offensive text exchanges which sparked a wave of protest on social media and on the streets.
However Mr Logan rejected claims that the IRFU had caved in to the baying Twitter mob or that the decision was motivated by money.
“No sponsor including Bank of Ireland drove the decision,” he added.
“We have taken on board everybody’s views right across society, right across our supporter group, our sponsor group, our players, clubs, volunteers, we are part of society.
“But at the end of the day, having looked at all those things, the decision was based on alignment with what it is we stand for, in particular the value of respect.
“The players themselves admitted in their own statements that they were way short of what was expected of them.” (PA)