You're thinking logically, it really is the rest of the world that's crazy in this case. Two teens, in a relationship, who can legally have sex with each other (and likely have) what is the fuss about?
Hmm, the federal law might actually apply in this case as it's a text that presumably crosses state lines. However, I grew up in a state where I could legally have sex at 16; even then there were romeo and juliet laws that would allow sex with an older individual if they are close in age. It's a little crazy to find that you can have sex but not over the phone.