(Submitted not to criticize, or revive discussion, but only to add my 2 cents)
From “Once Upon a Time”, season 2, episode 6 – “Tallahassee”
Emma Swan: I am not having drinks with you. You might be a pervert.
Neal Cassidy: I might be a pervert, but you're definitely a car thief.
I’m proceeding on the fact circumstance that Neal had sexual intercourse with Emma at least once in the state of Oregon (where the age of legal sexual consent was 18), during a time when Emma was 17 years old and Neal was at least 3 years older than Emma.
My first thought about this circumstance is to consider the creative intent from a show production standpoint. I doubt that there was ever any creative intent to establish a legally or morally controversial circumstance surrounding the relationship between Neal and Emma. I think that there were likely some geographical considerations that went into where to set this aspect of Emma’s backstory (and Neal’s backstory), such as wanting to set events in the western U.S. for Emma and Neal, and Vancouver, B.C., Canada later for a scene between Neal and August. It happens that among the 12 U.S. states where the age of legal sexual consent is 18, this includes Oregon, California, and Arizona (but not Washington). I think what happened was a creative “goof” from a production standpoint, and no more.
My second thought about this circumstance concerns the issue of illegality vs. immorality. It would seem that the illegality is clear, and that illegality would be ascribed to Neal, not Emma. Additionally, from my quick online search of Oregon law in this respect, mistake of age does not appear to be a defense. However, I note that among the various Oregon statutory rape laws I found by online search, the ones which DO NOT fit the facts involving Neal and Emma, ranging from most-serious criminal violations (class A felony) to least-serious criminal violations (class A misdemeanor), are as follows: (1) rape in the first degree (minor <12), (2) rape in the second degree (minor 12-13), (3) rape in the third degree (minor 14-15), (4) first degree unlawful sexual penetration (minor <12), (5) second degree unlawful sexual penetration (minor 12-13), (6) first degree sexual abuse (minor <14), and (7) second degree sexual abuse (minor 14-17 and defendant >21 who is or was the victim’s coach). The ONE remaining Oregon statutory rape law which would seem to fit the facts involving Neal and Emma is (8) third degree sexual abuse (minor 14-17 and defendant at least 3 years older). I note that this offense is classified by Oregon as a class A misdemeanor, with penalties including a fine of up to $6,250, up to one year in jail, or both. I note also that under Oregon Revised Statutes section 819.300, the offense of possession of a stolen vehicle (e.g., the yellow bug) is a class C felony, with penalties including a fine of up to $125,000, up to five years in prison, or both. Additionally, as mentioned earlier, that sexual conduct involving Neal and Emma which is legally third degree sexual abuse in Oregon and otherwise criminal in 11 other U.S. states (about 31.5% of the U.S. state population) is considered entirely legal in the other 38 states (about 68.5% of the U.S. state population). As such, although the illegality may be clear, immorality is more subjective.