Shopping cart noises…bad

Went out on the club ride this morning and had a good, ol’ fashioned two-bike crash with another rider. We had five riders total; I was leading the paceline with one rider to my left. We approached an intersection and we realized a bit late that this was where the route turns right. The rider to my left braked and started turning in; I knew he was coming across my line so I braked and started to turn in as well. That’s when the guy immediately behind me ran over me and sent me over the bars, our bikes making those “shopping cart noises” as they cartwheeled around us. Evidently he had his head turned as I started to brake and couldn’t get out of the way in time.
I’m told that it all looked pretty spectacular, but we were only lightly injured. I sustained some road rash on my right knee and chin, and a nice strawberry on my shoulder – but no clothing rips, and no damage to the bike beyond blips in both wheels that I need to true out. My clubmate fared pretty much the same, and we were able to complete the ride.
This seems like a rookie mistake; experienced riders don’t make any sudden, unannounced moves in the paceline. However, I’m not sure that missing the turn would have been a better option here. If I had done that, the guy on my left probably would have creamed into me as he crossed my line, expecting me to turn with him. Moral of the story: know your route and announce your turns.