"We have thrown the show's rulebook out and Ali continued to change and break the rules to do what she felt needed to be done," he toldPeople in a Monday report.
"Ali says she's happy, doesn't regret doing it and is stronger for it, but from the last-chance dates on, this finale plays out completely different than you've seen before and I'm not sure how fans will feel about it."
According to Harrison, Fedotowsky's The Bachelorette season is actually deserving of his frequently touted "most dramatic season yet" billing.
"I think it is. I figured if I kept saying it, it would eventually come true. And the finale will not disappoint. It's very dramatic and very good," he told People of the finale, which has been the subject of conflicting rumors and reports that Fedotowsky rejected both Roberto Martinez and Chris Lambton or accepted a marriage proposal from one of her final two suitors.
"There were several moments where we thought we might lose her," Harrison said of the season, which included Fedotowsky bootingJustin Rego after learning he secretly had two girlfriends back home and the unexpected exit of Frank Neuschaefer -- the Final 3 suitor who decided to dump The Bachelorette star and leave the show after determining he and his former girlfriend still had feelings for each other.
"After Frank left at such a late point, we didn't know how she'd react. We were a week away from finishing and having dinner discussions about what we'd do if she shut down and said, 'I'm out.'"
However Martinez and Lambton are both excellent suitors for The Bachelorette star, Harrison said.
There are no cons for either one, just different lifestyles. Roberto lives in Florida and has a different culture. Chris is a typical New England guy," he told People. "They are both great guys from fantastic families who love Ali to death. It couldn't be a better finale situation for her, but with what happened with Frank, her head was still spinning and it shook things up."
While Fedotowsky has denied it, Harrison feels there was a "good chance" she was going to select Neuschaefer as her final suitor before he decided to quit the show.
"[It's] hard to say, but there was a good chance because they did have good chemistry," he told People. "Things were going ridiculously good with everyone and she was looking for any reason to get rid of one of them. She needed a sign and Frank gave her one that made her realize how many questions she had about him. He was so insecure. She told me that he represented boyfriends from the past -- guys she had to nurture and fix."
In addition, Harrison also confirmed Martinez and Lambton -- assuming they aren't selected by Fedotowsky -- are being considered as the next star of The Bachelor, along with Final 4 suitor Kirk DeWindt.
"The top three -- Roberto, Chris or Kirk -- would be super Bachelors. I don't think I've ever gotten more messages from women offering to take whichever guy she doesn't choose. I know for a fact we have not made a decision, but all those guys are in the running," he told People. "Maybe, if she doesn't choose either one, we could have dueling Bachelors."