I believe it was rape because not so sober girl said no. she was taken against her will. It does not matter what happened a month down the line. Dating a month down the line could have been not so sober's girls way of trying to erase the rape in her own mind and turning it into a prequel to a relationship. If she ended up with sober boy and they lived out their lives together, then it was love, meant to be, that first indescretion could be overlooked, erased. but relationship didnt work, as you say, not so sober girl was a mess, because no matter why, her mind could not accept these rationalizations.

hugs...