"Standing at the rose ceremony as I looked at the final three women you could clearly see one of these just isn't like the other," Harrison wrote in his Entertainment Weekly blog.
"If you notice when Sean is with Catherine and Lindsay he laughs more and he seems more comfortable. Their relationships are much more playful and that's something that's appealing to Sean. It's not that he didn't have fun with AshLee -- he did, but it was different... To be honest I really think Sean got it right."
Harrison explained that Frazier's maturity and life experience is unfortunately what put her a step behind the other two women.
"When you look at these final three, I think Catherine and Lindsay really represent something different for Sean and bring out a much different side of him than AshLee does... I really think AshLee, being a little older than Sean and the other women, is in a little different place in her life. She carries herself differently, presents herself differently, and went through this whole process with a different mindset than the other two women," the host wrote.
"While this was all very appealing to Sean, in the end I think he realized after spending time with Catherine and Lindsay that he wasn't ready for that, and ultimately that's not exactly what he's looking for. Catherine and Lindsay definitely seem to be more on the same level as Sean. They seem to all be looking for exactly the same thing and are at the same station in their life."
Because Frazier was basically the oddball of the group, Lowe decided to let her go because he obviously wanted what his other two bachelorettes had to offer.
"AshLee was definitely the odd woman out. Clearly she had no idea what was coming. She had all the confidence in the world that Sean was going to choose her. So when Sean gave Catherine that final rose and sent her home she was completely blindsided," he said.
"It was that confusion that led to a somewhat emotional exit for AshLee. She was so confused and hurt that she not only didn't let Sean explain his decision, she didn't say a word herself... It seemed to be an honest emotional response to a tough situation."