I finally made it back, around 3 yesterday afternoon (after waiting in the taxi since 7 a.m.).
Sadly, it's easy to bully people here, even Zambian men, so I bullied the taxi driver into refunding me 10 pin of the fare because he wasn't planning to drive me home (not that I had asked, but I did stupidly pay the white-lady rate, thinking that we would leave at a reasonable hour and maybe not as crowded as usual). I was grumpy and tired, but probably not as much as the guy who had spent the entire trip as the third person in the front seat, straddling the gear box with his arse on the emergency brake. We spent a lot of time between first and second gears (I couldn't help but notice), with several episodes of reverse.
Speaking of crazy African taxis, I also took TWO rides this weekend in which FOUR people shared the two bucket seats in front. Take that, HOV lane!