"Lying" and "narcissistic behaviour" are just some of the things about Carl Lentz that concerned Hillsong founder Brian Houston.
Lentz was fired as the pastor of Hillsong NYC last November for moral failures, and admitted to cheating on his wife.
The scandal led to further allegations against the wider leadership of the New York church, including sexual relations between staff and volunteers, a culture of pandering to celebrities, and lavish spending of church funds.
The allegations were investigated but the findings were not made public.
Houston has already apologized for failings at the East Coast campus and promised to make changes.
Commenting further on the scandal on Wednesday, Houston told NBC's "TODAY" programme that although there were a lot of things he missed about Lentz, there were serious issues too.
"Having said that, there were leadership issues that I believe included lying, included what I would call narcissistic behavior," Houston said.
"I'd have to admit I've had concerns and many conversations over the years with Carl. I think there's a lot of things I should have known earlier, and hopefully moving forward we make sure we have far better systems in place and better accountability."
Houston also addressed complaints of bullying and said he was "100 per cent committed to moving that out of our church."
Asked about whether the church was guilty of trying to appeal to celebrities like Justin Bieber, Houston said there was a positive side to the story.
"[Bieber] was wrecking hotel rooms and basically on the edge of getting deported to Canada," Houston said.
"And look at Justin Bieber today. Anyone who's being fair could see a radical change. And so not everything about it is bad."
But he added, "I do think that we did allow a culture to develop where it was one rule for celebrities and a different rule for other people."
Allegations of failures have not been limited to Hillsong NYC. A cloud of controversy surrounded the recent resignation of pastors at other branches too.
Dallas operations were suspended in April after complaints about the leadership of former pastors Reed and Jess Bogard.
Around the same time, the creative director of Hillsong's Montclair church in New Jersey resigned over inappropriate photos that were sent to a volunteer.
Houston told "TODAY", "I'm acknowledging that mistakes have been made and that there are things where we need to get far better, much better. I'm not shrinking back from that."