Here is what I remember. You tell me if I am wrong.
DW had just broken up with a girlfriend. Thus the recent trips to the bar.
That Friday, he was drinking RUM and COKE as usual. He can handle that. Someone had been given a shot and didn't want it, so the waitress gave it to DW. He isn't used to them. He did it anyway. It hit him quickly, and that is likely the reason he left.
He had gotten a previous DUI. You don't have to be DRUNK, or OUT OF CONTROL to be pulled over and given a DUI. If, in the officer's opinion, your ability to operate a motor vehicle is in any way impaired (i.e. a judgment call, usually based on the departments need for income, and whether the officer personally knows you or you are female), you can be given a DUI. Doesn't matter whether you get a breath test and it proves you are over the limit or not.
So, what you said was totally unsubtantiated.
Keith and Rich were hot for Barb and Denise. One of them had been promised a hookup with Barb.
Men don't like other men horning in, believe me.
So, Rich had access to drugs. Ever heard of GMBH, RUFFY'S ??????
I have had friends who had someone put that in their drinks. One woman went to the bathroom,and came out later with her underpants down to her knees and just sat down at the table, completely oblivious.
She had to be put in a car and driven home.
Another barely made it home. He got inside his door and set down on the floor for the next 4 hours.
The woman was spiked because someone wanted to get her in their car and have their way, the guy was spiked, because he was in the way.