They have been accused of victim blaming over their line of questioning, asking the 18-year-old, who went by the name of Amy, if the girls were "willing" drinkers, why they had not made formal complaints to the police and asked when Amy had lost her virginity.
Amy said she believed those involved were rapists, which was met with a small laugh by the hosts, who then said: "Well if some of the girls have consented that doesn't make them rapists, right?"
Ms Ihaka said the hosts comments were "disgusting".
"It's not fair that they [the radio hosts] have blamed these girls, it's not okay, and it doesn't portray a very good look for other people that may want to come forward, that are in similar situations.
"It's absolutely disgusting."
Ms Ihaka said she had dealt with a couple of recent Wairarapa rape cases involving teenage victims and said it can be even harder for young girls to report sexual assaults. "It's a very slim amount of people that will actually talk about it, when something has happened, and especially with young girls, it's all about the shame of it. A lot of their life revolves around their circle of friends, so if these girls come out a majority of the time a lot of people are going to call them names because kids are judgmental and they don't understand the real issue."
She said a small number of the rape cases she had dealt were related to alcohol.
"Legally they can't consent if they are under the influence of something.
"It doesn't matter if these girls [the Roast Busters victims] agreed to drink alcohol - it still doesn't mean that these boys can take advantage of these girls. I can pretty much guarantee that the majority of girls wouldn't have wanted to do it and wouldn't have made that decision sober."
Ms Ihaka hoped the Roast Busters would be held accountable for their actions but said the publicity surrounding the sex scandal would make it even harder for the girls to come forward.
"It's going to be really hard for these girls to do that, they are going to have to be really strong to do that because it's in the public eye.
"It's not just their friends, or groups, that have opinions now, it's the whole country.
"They need to come forward and talk about it when they are ready, not when other people think they should."