Transcript for College athlete, coach disagree whether sexual relationship was consensual: Part 2
Reporter: It's the spring of 2012. Hundreds of the country's top tier athletes are in Eugene Oregon, nicknamed track town usa, to compete for the chance to represent the red white & blue, and maybe one day, capture gold. The olympic trials, this is where the best of the best in amateur athletes come to compete to try to punch their tickets to go to the olympic games. Reporter: 20-year-old Arizona wild cat baillie Gibson is one of them, but baillie's coming off a year marked by injury and disappointment, and her performance is less than memorable, coming in a distant 12th in the discus, and 9th in the shot put. I didn't do as well as I had wanted. She was very upset in terms of not competing very well. She knew she had a lot more potential there so she was disappointed with her performance definitely. Reporter: And what happened next is still a subject of intense dispute, controversy and pain. Here is what bailee told us happened at after the competition ends. Writhing from the agony of defeat, baillie joins other teammates at a house party. Now had you all been drinking? Yes. How intoxicated were you? I didn't think I was bad at all, like at all. I mean, yeah I'd been drinking, but it wasn't a lot, and I don't know, because it was like, red solo cups, you know. Reporter: Her friends want to hit bars, but bailee, underage and under the influence makes a different call to her coach, Craig Carter. And why'd you call him? Because that's what everyone told me to do and what a lot of other athletes do, is you call the coach. Reporter: She says coach Carter quickly comes to get her. She would later admit she was drunk, and says getting in his car is the last thing she remembers. And I get in the car and then we're driving, and then all of a sudden, I don't know what happens. Reporter: The next day she sees her coach at the airport, and if a hangover and those disappointing standings weren't heavy enough, baillie says coach Carter is sending her back to Tucson with baggage of a very different kind, humiliating and shocking. He's like how do you feel, and I was just like well other than I have a huge headache, I feel fine you know, and he's like well do you -- you don't remember last night. No. Not at all. Reporter: She says Carter tells her they had sex in the backseat of his car, and what's more, he's got the pictures to prove it. What were the pictures? Give me a sense of what you saw of yourself. Me laying there with no clothes on. In the backseat of a car. Reporter: So they were pictures of him having sex with you. Yeah, intercourse. What's your, what's your reaction when he's showing these pictures to you? I want to puke. I'm like devastated. What did he say to you next? And he's like if you tell anyone like, I'll send these pictures out and show what a whore you are and a slut. And you believed him. Yeah cause I didn't know anything else. I -- and I didn't want my body to be everywhere, or to lose my scholarship, and go back to my hometown feeling like a failure. Reporter: She says the 4 hour flight back to tuscon's a blur, and when she returns to campus, she says it's not just the fear over her coach's alleged threats keeping her up at night, there's also shame. I thought it was my fault. I was like what did I do? Why would I ever do that? Like, that's not who I am. That's not what I'm like, about. Does it occur to you to maybe call your parents? I wanted to, but, I was scared what they would think. I don't want to look bad in their eyes. Reporter: But coach Carter tells a remarkably different story about the nature of their relationship and how it began -- he says baillie initiated, instigated and actively pursued a sexual relationship with him, alleging she viewed him as a prized conquest. She's like I just want to have sex whenever you want to have sex just for fun. Reporter: Soon he says the sex talk turns into action, a physical and consensual relationship. But however it began it's not going to end well. Baillie heads home to Wyoming for the summer. But even 1,000 miles away she claims Carter is making insidious demands insisting she text nude pictures of herself or else he'll share those compromising photos. You didn't say anything to your parents? Nope. Is it difficult for you keeping that secret? Yeah. It's hard when you can't tell the people you love what's really going on with you. Reporter: When she arrives back on campus she says coach Carter calling her to his office. He's like you didn't tell anyone? No I didn't tell anybody and he's like good because we're going to have sex more and I was like I don't want that. Reporter: Are you thinking of maybe robeeporting him to the university? I thought about that. What are they going to say? Well, you wanted it. Reporter: Your word against his? Yeah, he's got the power. Reporter: How often were you seeing each other sexually? Like twice, three times a week. He would send a text, 7:00 team office. Reporter: Carter would insist there was a genuine emotional bond between them. I don't know how he didn't pick up I did not want him. Reporter: Back in Wyoming baillie's parents are concerned when their third year college student is home sick. She started to want to come home a lot. She would show up. Surprise. And I thought well she just needs to come home. She misses home. But then when she would get a phone call and run to the other room, like, who is that? She says it's coach. I said so what's the coach saying? He's got to talk to me telling me my workouts. I just shrugged it off and thought it was kind of weird. Did she seem her usual self around that time? I noticed she was more like down on herself. She was not as like the Miley baillie I knew. How was her relationship with coach Carter, anything any different? They would butt heads a lot. She would say I'm not allowed to talk about practice. He told me I'm not allowed to smile and I thought that was very, very weird. The coach told her that? Yes. That was weird to me because he didn't say anything along those lines to any of the other athletes. Coming up, baillie says she finds the courage to call a halt to the arrangement but her coach won't take no for an answer. He grabbed you and put a box cutter to your throat? Yes. What's going on in your mind?
This transcript has been automatically generated and may not be 100% accurate.