I don't see how the original timeline George and Lorraine got together

He was drinking and looking at magazines before Lorraine went inside to the dance, so it had only just begun. Then he got knocked out and started chasing Marty, so Biff missed most of the dance because of that. So again, this is part of the alternate timeline that prevents Biff from interfering with George and Lorraine, which he had been doing all the time up until that point.

Still! Regardless if Biff went to the dance and for some unknown reason, stood alone, did nothing to harass/bully George like he usually did, and kept away from his "meant to be" Lorraine so they could kiss, we're supposed to believe that an unpunched Biff is just going go stag to a dance, go home alone and accept that George and Lorraine are in love and do nothing about it, up until she gets into an accident and starts to look like crap and he loses interest or something? Because that's how the original time line makes it seem, except he still was interested after the accident with the "say hi to your mom for me" line.

Are we supposed to believe that Biff is just some run of the mill bully that just wants his work done, who suddenly gets pushed over the edge to a complete psychopath rapist from a truck of manure? Sorry, I ain't buying it. Guys like Biff are relentless. There is NO WAY in hell the Biff we see during the Calvin Klein 50s time period, would ever allow someone like George to keep Lorraine. He would make George his bitch, and without Marty around to teach him to stand up for himself, he would cuck the hell out of ol Georgie by raping Lorraine and forcing George to raise Biff's kids Dave and Linda, as his own. Marty's Parents little story about getting together would be much different.

It'd be more like, I got into a wreck and your dad took care of me after Biff lost interest and abandoned me and your brother and sister. That's the more logical outcome of the original lives of all 3.